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