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