1 /*- 2 * Copyright (c) 2007 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("$FreeBSD$"); 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 50 struct g_part_mbr_table { 51 struct g_part_table base; 52 u_char mbr[MBRSIZE]; 53 }; 54 55 struct g_part_mbr_entry { 56 struct g_part_entry base; 57 struct dos_partition ent; 58 }; 59 60 static int g_part_mbr_add(struct g_part_table *, struct g_part_entry *, 61 struct g_part_parms *); 62 static int g_part_mbr_bootcode(struct g_part_table *, struct g_part_parms *); 63 static int g_part_mbr_create(struct g_part_table *, struct g_part_parms *); 64 static int g_part_mbr_destroy(struct g_part_table *, struct g_part_parms *); 65 static int g_part_mbr_dumpconf(struct g_part_table *, struct g_part_entry *, 66 struct sbuf *, const char *); 67 static int g_part_mbr_dumpto(struct g_part_table *, struct g_part_entry *); 68 static int g_part_mbr_modify(struct g_part_table *, struct g_part_entry *, 69 struct g_part_parms *); 70 static char *g_part_mbr_name(struct g_part_table *, struct g_part_entry *, 71 char *, size_t); 72 static int g_part_mbr_probe(struct g_part_table *, struct g_consumer *); 73 static int g_part_mbr_read(struct g_part_table *, struct g_consumer *); 74 static const char *g_part_mbr_type(struct g_part_table *, struct g_part_entry *, 75 char *, size_t); 76 static int g_part_mbr_write(struct g_part_table *, struct g_consumer *); 77 78 static kobj_method_t g_part_mbr_methods[] = { 79 KOBJMETHOD(g_part_add, g_part_mbr_add), 80 KOBJMETHOD(g_part_bootcode, g_part_mbr_bootcode), 81 KOBJMETHOD(g_part_create, g_part_mbr_create), 82 KOBJMETHOD(g_part_destroy, g_part_mbr_destroy), 83 KOBJMETHOD(g_part_dumpconf, g_part_mbr_dumpconf), 84 KOBJMETHOD(g_part_dumpto, g_part_mbr_dumpto), 85 KOBJMETHOD(g_part_modify, g_part_mbr_modify), 86 KOBJMETHOD(g_part_name, g_part_mbr_name), 87 KOBJMETHOD(g_part_probe, g_part_mbr_probe), 88 KOBJMETHOD(g_part_read, g_part_mbr_read), 89 KOBJMETHOD(g_part_type, g_part_mbr_type), 90 KOBJMETHOD(g_part_write, g_part_mbr_write), 91 { 0, 0 } 92 }; 93 94 static struct g_part_scheme g_part_mbr_scheme = { 95 "MBR", 96 g_part_mbr_methods, 97 sizeof(struct g_part_mbr_table), 98 .gps_entrysz = sizeof(struct g_part_mbr_entry), 99 .gps_minent = NDOSPART, 100 .gps_maxent = NDOSPART, 101 .gps_bootcodesz = MBRSIZE, 102 }; 103 G_PART_SCHEME_DECLARE(g_part_mbr); 104 105 static int 106 mbr_parse_type(const char *type, u_char *dp_typ) 107 { 108 const char *alias; 109 char *endp; 110 long lt; 111 112 if (type[0] == '!') { 113 lt = strtol(type + 1, &endp, 0); 114 if (type[1] == '\0' || *endp != '\0' || lt <= 0 || lt >= 256) 115 return (EINVAL); 116 *dp_typ = (u_char)lt; 117 return (0); 118 } 119 alias = g_part_alias_name(G_PART_ALIAS_FREEBSD); 120 if (!strcasecmp(type, alias)) { 121 *dp_typ = DOSPTYP_386BSD; 122 return (0); 123 } 124 return (EINVAL); 125 } 126 127 static int 128 mbr_probe_bpb(u_char *bpb) 129 { 130 uint16_t secsz; 131 uint8_t clstsz; 132 133 #define PO2(x) ((x & (x - 1)) == 0) 134 secsz = le16dec(bpb); 135 if (secsz < 512 || secsz > 4096 || !PO2(secsz)) 136 return (0); 137 clstsz = bpb[2]; 138 if (clstsz < 1 || clstsz > 128 || !PO2(clstsz)) 139 return (0); 140 #undef PO2 141 142 return (1); 143 } 144 145 static void 146 mbr_set_chs(struct g_part_table *table, uint32_t lba, u_char *cylp, u_char *hdp, 147 u_char *secp) 148 { 149 uint32_t cyl, hd, sec; 150 151 sec = lba % table->gpt_sectors + 1; 152 lba /= table->gpt_sectors; 153 hd = lba % table->gpt_heads; 154 lba /= table->gpt_heads; 155 cyl = lba; 156 if (cyl > 1023) 157 sec = hd = cyl = ~0; 158 159 *cylp = cyl & 0xff; 160 *hdp = hd & 0xff; 161 *secp = (sec & 0x3f) | ((cyl >> 2) & 0xc0); 162 } 163 164 static int 165 g_part_mbr_add(struct g_part_table *basetable, struct g_part_entry *baseentry, 166 struct g_part_parms *gpp) 167 { 168 struct g_part_mbr_entry *entry; 169 struct g_part_mbr_table *table; 170 uint32_t start, size, sectors; 171 172 if (gpp->gpp_parms & G_PART_PARM_LABEL) 173 return (EINVAL); 174 175 sectors = basetable->gpt_sectors; 176 177 entry = (struct g_part_mbr_entry *)baseentry; 178 table = (struct g_part_mbr_table *)basetable; 179 180 start = gpp->gpp_start; 181 size = gpp->gpp_size; 182 if (size < sectors) 183 return (EINVAL); 184 if (start % sectors) { 185 size = size - sectors + (start % sectors); 186 start = start - (start % sectors) + sectors; 187 } 188 if (size % sectors) 189 size = size - (size % sectors); 190 if (size < sectors) 191 return (EINVAL); 192 193 if (baseentry->gpe_deleted) 194 bzero(&entry->ent, sizeof(entry->ent)); 195 196 KASSERT(baseentry->gpe_start <= start, (__func__)); 197 KASSERT(baseentry->gpe_end >= start + size - 1, (__func__)); 198 baseentry->gpe_start = start; 199 baseentry->gpe_end = start + size - 1; 200 entry->ent.dp_start = start; 201 entry->ent.dp_size = size; 202 mbr_set_chs(basetable, baseentry->gpe_start, &entry->ent.dp_scyl, 203 &entry->ent.dp_shd, &entry->ent.dp_ssect); 204 mbr_set_chs(basetable, baseentry->gpe_end, &entry->ent.dp_ecyl, 205 &entry->ent.dp_ehd, &entry->ent.dp_esect); 206 return (mbr_parse_type(gpp->gpp_type, &entry->ent.dp_typ)); 207 } 208 209 static int 210 g_part_mbr_bootcode(struct g_part_table *basetable, struct g_part_parms *gpp) 211 { 212 struct g_part_mbr_table *table; 213 214 table = (struct g_part_mbr_table *)basetable; 215 bcopy(gpp->gpp_codeptr, table->mbr, DOSPARTOFF); 216 return (0); 217 } 218 219 static int 220 g_part_mbr_create(struct g_part_table *basetable, struct g_part_parms *gpp) 221 { 222 struct g_consumer *cp; 223 struct g_provider *pp; 224 struct g_part_mbr_table *table; 225 uint64_t msize; 226 227 pp = gpp->gpp_provider; 228 cp = LIST_FIRST(&pp->consumers); 229 230 if (pp->sectorsize < MBRSIZE) 231 return (ENOSPC); 232 233 msize = pp->mediasize / pp->sectorsize; 234 basetable->gpt_first = basetable->gpt_sectors; 235 basetable->gpt_last = msize - (msize % basetable->gpt_sectors) - 1; 236 237 table = (struct g_part_mbr_table *)basetable; 238 le16enc(table->mbr + DOSMAGICOFFSET, DOSMAGIC); 239 return (0); 240 } 241 242 static int 243 g_part_mbr_destroy(struct g_part_table *basetable, struct g_part_parms *gpp) 244 { 245 246 /* Wipe the first sector to clear the partitioning. */ 247 basetable->gpt_smhead |= 1; 248 return (0); 249 } 250 251 static int 252 g_part_mbr_dumpconf(struct g_part_table *table, struct g_part_entry *baseentry, 253 struct sbuf *sb, const char *indent) 254 { 255 struct g_part_mbr_entry *entry; 256 257 if (indent != NULL) 258 return (0); 259 260 entry = (struct g_part_mbr_entry *)baseentry; 261 sbuf_printf(sb, " xs MBR xt %u", entry->ent.dp_typ); 262 return (0); 263 } 264 265 static int 266 g_part_mbr_dumpto(struct g_part_table *table, struct g_part_entry *baseentry) 267 { 268 struct g_part_mbr_entry *entry; 269 270 /* Allow dumping to a FreeBSD partition only. */ 271 entry = (struct g_part_mbr_entry *)baseentry; 272 return ((entry->ent.dp_typ == DOSPTYP_386BSD) ? 1 : 0); 273 } 274 275 static int 276 g_part_mbr_modify(struct g_part_table *basetable, 277 struct g_part_entry *baseentry, struct g_part_parms *gpp) 278 { 279 struct g_part_mbr_entry *entry; 280 281 if (gpp->gpp_parms & G_PART_PARM_LABEL) 282 return (EINVAL); 283 284 entry = (struct g_part_mbr_entry *)baseentry; 285 if (gpp->gpp_parms & G_PART_PARM_TYPE) 286 return (mbr_parse_type(gpp->gpp_type, &entry->ent.dp_typ)); 287 return (0); 288 } 289 290 static char * 291 g_part_mbr_name(struct g_part_table *table, struct g_part_entry *baseentry, 292 char *buf, size_t bufsz) 293 { 294 295 snprintf(buf, bufsz, "s%d", baseentry->gpe_index); 296 return (buf); 297 } 298 299 static int 300 g_part_mbr_probe(struct g_part_table *table, struct g_consumer *cp) 301 { 302 struct g_provider *pp; 303 u_char *buf, *p; 304 int error, index, res, sum; 305 uint16_t magic; 306 307 pp = cp->provider; 308 309 /* Sanity-check the provider. */ 310 if (pp->sectorsize < MBRSIZE || pp->mediasize < pp->sectorsize) 311 return (ENOSPC); 312 if (pp->sectorsize > 4096) 313 return (ENXIO); 314 315 /* Check that there's a MBR. */ 316 buf = g_read_data(cp, 0L, pp->sectorsize, &error); 317 if (buf == NULL) 318 return (error); 319 320 /* We goto out on mismatch. */ 321 res = ENXIO; 322 323 magic = le16dec(buf + DOSMAGICOFFSET); 324 if (magic != DOSMAGIC) 325 goto out; 326 327 for (index = 0; index < NDOSPART; index++) { 328 p = buf + DOSPARTOFF + index * DOSPARTSIZE; 329 if (p[0] != 0 && p[0] != 0x80) 330 goto out; 331 } 332 333 /* 334 * If the partition table does not consist of all zeroes, 335 * assume we have a MBR. If it's all zeroes, we could have 336 * a boot sector. For example, a boot sector that doesn't 337 * have boot code -- common on non-i386 hardware. In that 338 * case we check if we have a possible BPB. If so, then we 339 * assume we have a boot sector instead. 340 */ 341 sum = 0; 342 for (index = 0; index < NDOSPART * DOSPARTSIZE; index++) 343 sum += buf[DOSPARTOFF + index]; 344 if (sum != 0 || !mbr_probe_bpb(buf + 0x0b)) 345 res = G_PART_PROBE_PRI_NORM; 346 347 out: 348 g_free(buf); 349 return (res); 350 } 351 352 static int 353 g_part_mbr_read(struct g_part_table *basetable, struct g_consumer *cp) 354 { 355 struct dos_partition ent; 356 struct g_provider *pp; 357 struct g_part_mbr_table *table; 358 struct g_part_mbr_entry *entry; 359 u_char *buf, *p; 360 off_t chs, msize; 361 u_int sectors, heads; 362 int error, index; 363 364 pp = cp->provider; 365 table = (struct g_part_mbr_table *)basetable; 366 msize = pp->mediasize / pp->sectorsize; 367 368 buf = g_read_data(cp, 0L, pp->sectorsize, &error); 369 if (buf == NULL) 370 return (error); 371 372 bcopy(buf, table->mbr, sizeof(table->mbr)); 373 for (index = NDOSPART - 1; index >= 0; index--) { 374 p = buf + DOSPARTOFF + index * DOSPARTSIZE; 375 ent.dp_flag = p[0]; 376 ent.dp_shd = p[1]; 377 ent.dp_ssect = p[2]; 378 ent.dp_scyl = p[3]; 379 ent.dp_typ = p[4]; 380 ent.dp_ehd = p[5]; 381 ent.dp_esect = p[6]; 382 ent.dp_ecyl = p[7]; 383 ent.dp_start = le32dec(p + 8); 384 ent.dp_size = le32dec(p + 12); 385 if (ent.dp_typ == 0 || ent.dp_typ == DOSPTYP_PMBR) 386 continue; 387 if (ent.dp_start == 0 || ent.dp_size == 0) 388 continue; 389 sectors = ent.dp_esect & 0x3f; 390 if (sectors > basetable->gpt_sectors && 391 !basetable->gpt_fixgeom) { 392 g_part_geometry_heads(msize, sectors, &chs, &heads); 393 if (chs != 0) { 394 basetable->gpt_sectors = sectors; 395 basetable->gpt_heads = heads; 396 } 397 } 398 if ((ent.dp_start % basetable->gpt_sectors) != 0) 399 printf("GEOM: %s: partition %d does not start on a " 400 "track boundary.\n", pp->name, index + 1); 401 if ((ent.dp_size % basetable->gpt_sectors) != 0) 402 printf("GEOM: %s: partition %d does not end on a " 403 "track boundary.\n", pp->name, index + 1); 404 405 entry = (struct g_part_mbr_entry *)g_part_new_entry(basetable, 406 index + 1, ent.dp_start, ent.dp_start + ent.dp_size - 1); 407 entry->ent = ent; 408 } 409 410 basetable->gpt_entries = NDOSPART; 411 basetable->gpt_first = basetable->gpt_sectors; 412 basetable->gpt_last = msize - (msize % basetable->gpt_sectors) - 1; 413 414 return (0); 415 } 416 417 static const char * 418 g_part_mbr_type(struct g_part_table *basetable, struct g_part_entry *baseentry, 419 char *buf, size_t bufsz) 420 { 421 struct g_part_mbr_entry *entry; 422 int type; 423 424 entry = (struct g_part_mbr_entry *)baseentry; 425 type = entry->ent.dp_typ; 426 if (type == DOSPTYP_386BSD) 427 return (g_part_alias_name(G_PART_ALIAS_FREEBSD)); 428 snprintf(buf, bufsz, "!%d", type); 429 return (buf); 430 } 431 432 static int 433 g_part_mbr_write(struct g_part_table *basetable, struct g_consumer *cp) 434 { 435 struct g_part_entry *baseentry; 436 struct g_part_mbr_entry *entry; 437 struct g_part_mbr_table *table; 438 u_char *p; 439 int error, index; 440 441 table = (struct g_part_mbr_table *)basetable; 442 baseentry = LIST_FIRST(&basetable->gpt_entry); 443 for (index = 1; index <= basetable->gpt_entries; index++) { 444 p = table->mbr + DOSPARTOFF + (index - 1) * DOSPARTSIZE; 445 entry = (baseentry != NULL && index == baseentry->gpe_index) 446 ? (struct g_part_mbr_entry *)baseentry : NULL; 447 if (entry != NULL && !baseentry->gpe_deleted) { 448 p[0] = entry->ent.dp_flag; 449 p[1] = entry->ent.dp_shd; 450 p[2] = entry->ent.dp_ssect; 451 p[3] = entry->ent.dp_scyl; 452 p[4] = entry->ent.dp_typ; 453 p[5] = entry->ent.dp_ehd; 454 p[6] = entry->ent.dp_esect; 455 p[7] = entry->ent.dp_ecyl; 456 le32enc(p + 8, entry->ent.dp_start); 457 le32enc(p + 12, entry->ent.dp_size); 458 } else 459 bzero(p, DOSPARTSIZE); 460 461 if (entry != NULL) 462 baseentry = LIST_NEXT(baseentry, gpe_entry); 463 } 464 465 error = g_write_data(cp, 0, table->mbr, cp->provider->sectorsize); 466 return (error); 467 } 468