2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
4 * Copyright (c) 2007, 2008 Marcel Moolenaar
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
11 * 1. Redistributions of source code must retain the above copyright
12 * notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 * notice, this list of conditions and the following disclaimer in the
15 * documentation and/or other materials provided with the distribution.
17 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
18 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
19 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
20 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
21 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
22 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
23 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
24 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
26 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
29 #include <sys/cdefs.h>
30 __FBSDID("$FreeBSD$");
32 #include <sys/param.h>
34 #include <sys/diskmbr.h>
35 #include <sys/endian.h>
36 #include <sys/kernel.h>
38 #include <sys/limits.h>
40 #include <sys/malloc.h>
41 #include <sys/mutex.h>
42 #include <sys/queue.h>
44 #include <sys/systm.h>
45 #include <sys/sysctl.h>
46 #include <geom/geom.h>
47 #include <geom/geom_int.h>
48 #include <geom/part/g_part.h>
50 #include "g_part_if.h"
52 FEATURE(geom_part_mbr, "GEOM partitioning class for MBR support");
54 SYSCTL_DECL(_kern_geom_part);
55 static SYSCTL_NODE(_kern_geom_part, OID_AUTO, mbr, CTLFLAG_RW, 0,
56 "GEOM_PART_MBR Master Boot Record");
58 static u_int enforce_chs = 0;
59 SYSCTL_UINT(_kern_geom_part_mbr, OID_AUTO, enforce_chs,
60 CTLFLAG_RWTUN, &enforce_chs, 0, "Enforce alignment to CHS addressing");
64 struct g_part_mbr_table {
65 struct g_part_table base;
69 struct g_part_mbr_entry {
70 struct g_part_entry base;
71 struct dos_partition ent;
74 static int g_part_mbr_add(struct g_part_table *, struct g_part_entry *,
75 struct g_part_parms *);
76 static int g_part_mbr_bootcode(struct g_part_table *, struct g_part_parms *);
77 static int g_part_mbr_create(struct g_part_table *, struct g_part_parms *);
78 static int g_part_mbr_destroy(struct g_part_table *, struct g_part_parms *);
79 static void g_part_mbr_dumpconf(struct g_part_table *, struct g_part_entry *,
80 struct sbuf *, const char *);
81 static int g_part_mbr_dumpto(struct g_part_table *, struct g_part_entry *);
82 static int g_part_mbr_modify(struct g_part_table *, struct g_part_entry *,
83 struct g_part_parms *);
84 static const char *g_part_mbr_name(struct g_part_table *, struct g_part_entry *,
86 static int g_part_mbr_probe(struct g_part_table *, struct g_consumer *);
87 static int g_part_mbr_read(struct g_part_table *, struct g_consumer *);
88 static int g_part_mbr_setunset(struct g_part_table *, struct g_part_entry *,
89 const char *, unsigned int);
90 static const char *g_part_mbr_type(struct g_part_table *, struct g_part_entry *,
92 static int g_part_mbr_write(struct g_part_table *, struct g_consumer *);
93 static int g_part_mbr_resize(struct g_part_table *, struct g_part_entry *,
94 struct g_part_parms *);
96 static kobj_method_t g_part_mbr_methods[] = {
97 KOBJMETHOD(g_part_add, g_part_mbr_add),
98 KOBJMETHOD(g_part_bootcode, g_part_mbr_bootcode),
99 KOBJMETHOD(g_part_create, g_part_mbr_create),
100 KOBJMETHOD(g_part_destroy, g_part_mbr_destroy),
101 KOBJMETHOD(g_part_dumpconf, g_part_mbr_dumpconf),
102 KOBJMETHOD(g_part_dumpto, g_part_mbr_dumpto),
103 KOBJMETHOD(g_part_modify, g_part_mbr_modify),
104 KOBJMETHOD(g_part_resize, g_part_mbr_resize),
105 KOBJMETHOD(g_part_name, g_part_mbr_name),
106 KOBJMETHOD(g_part_probe, g_part_mbr_probe),
107 KOBJMETHOD(g_part_read, g_part_mbr_read),
108 KOBJMETHOD(g_part_setunset, g_part_mbr_setunset),
109 KOBJMETHOD(g_part_type, g_part_mbr_type),
110 KOBJMETHOD(g_part_write, g_part_mbr_write),
114 static struct g_part_scheme g_part_mbr_scheme = {
117 sizeof(struct g_part_mbr_table),
118 .gps_entrysz = sizeof(struct g_part_mbr_entry),
119 .gps_minent = NDOSPART,
120 .gps_maxent = NDOSPART,
121 .gps_bootcodesz = MBRSIZE,
123 G_PART_SCHEME_DECLARE(g_part_mbr);
124 MODULE_VERSION(geom_part_mbr, 0);
126 static struct g_part_mbr_alias {
129 } mbr_alias_match[] = {
130 { DOSPTYP_386BSD, G_PART_ALIAS_FREEBSD },
131 { DOSPTYP_EXT, G_PART_ALIAS_EBR },
132 { DOSPTYP_NTFS, G_PART_ALIAS_MS_NTFS },
133 { DOSPTYP_FAT16, G_PART_ALIAS_MS_FAT16 },
134 { DOSPTYP_FAT32, G_PART_ALIAS_MS_FAT32 },
135 { DOSPTYP_FAT32LBA, G_PART_ALIAS_MS_FAT32LBA },
136 { DOSPTYP_EXTLBA, G_PART_ALIAS_EBR },
137 { DOSPTYP_LDM, G_PART_ALIAS_MS_LDM_DATA },
138 { DOSPTYP_LINSWP, G_PART_ALIAS_LINUX_SWAP },
139 { DOSPTYP_LINUX, G_PART_ALIAS_LINUX_DATA },
140 { DOSPTYP_LINLVM, G_PART_ALIAS_LINUX_LVM },
141 { DOSPTYP_LINRAID, G_PART_ALIAS_LINUX_RAID },
142 { DOSPTYP_PPCBOOT, G_PART_ALIAS_PREP_BOOT },
143 { DOSPTYP_VMFS, G_PART_ALIAS_VMFS },
144 { DOSPTYP_VMKDIAG, G_PART_ALIAS_VMKDIAG },
145 { DOSPTYP_APPLE_UFS, G_PART_ALIAS_APPLE_UFS },
146 { DOSPTYP_APPLE_BOOT, G_PART_ALIAS_APPLE_BOOT },
147 { DOSPTYP_HFS, G_PART_ALIAS_APPLE_HFS },
151 mbr_parse_type(const char *type, u_char *dp_typ)
158 if (type[0] == '!') {
159 lt = strtol(type + 1, &endp, 0);
160 if (type[1] == '\0' || *endp != '\0' || lt <= 0 || lt >= 256)
162 *dp_typ = (u_char)lt;
165 for (i = 0; i < nitems(mbr_alias_match); i++) {
166 alias = g_part_alias_name(mbr_alias_match[i].alias);
167 if (strcasecmp(type, alias) == 0) {
168 *dp_typ = mbr_alias_match[i].typ;
176 mbr_probe_bpb(u_char *bpb)
181 #define PO2(x) ((x & (x - 1)) == 0)
182 secsz = le16dec(bpb);
183 if (secsz < 512 || secsz > 4096 || !PO2(secsz))
186 if (clstsz < 1 || clstsz > 128 || !PO2(clstsz))
194 mbr_set_chs(struct g_part_table *table, uint32_t lba, u_char *cylp, u_char *hdp,
197 uint32_t cyl, hd, sec;
199 sec = lba % table->gpt_sectors + 1;
200 lba /= table->gpt_sectors;
201 hd = lba % table->gpt_heads;
202 lba /= table->gpt_heads;
209 *secp = (sec & 0x3f) | ((cyl >> 2) & 0xc0);
213 mbr_align(struct g_part_table *basetable, uint32_t *start, uint32_t *size)
217 if (enforce_chs == 0)
219 sectors = basetable->gpt_sectors;
222 if (start != NULL && (*start % sectors)) {
223 *size += (*start % sectors) - sectors;
224 *start -= (*start % sectors) - sectors;
227 *size -= (*size % sectors);
234 g_part_mbr_add(struct g_part_table *basetable, struct g_part_entry *baseentry,
235 struct g_part_parms *gpp)
237 struct g_part_mbr_entry *entry;
238 uint32_t start, size;
240 if (gpp->gpp_parms & G_PART_PARM_LABEL)
243 entry = (struct g_part_mbr_entry *)baseentry;
244 start = gpp->gpp_start;
245 size = gpp->gpp_size;
246 if (mbr_align(basetable, &start, &size) != 0)
248 if (baseentry->gpe_deleted)
249 bzero(&entry->ent, sizeof(entry->ent));
251 KASSERT(baseentry->gpe_start <= start, ("%s", __func__));
252 KASSERT(baseentry->gpe_end >= start + size - 1, ("%s", __func__));
253 baseentry->gpe_start = start;
254 baseentry->gpe_end = start + size - 1;
255 entry->ent.dp_start = start;
256 entry->ent.dp_size = size;
257 mbr_set_chs(basetable, baseentry->gpe_start, &entry->ent.dp_scyl,
258 &entry->ent.dp_shd, &entry->ent.dp_ssect);
259 mbr_set_chs(basetable, baseentry->gpe_end, &entry->ent.dp_ecyl,
260 &entry->ent.dp_ehd, &entry->ent.dp_esect);
261 return (mbr_parse_type(gpp->gpp_type, &entry->ent.dp_typ));
265 g_part_mbr_bootcode(struct g_part_table *basetable, struct g_part_parms *gpp)
267 struct g_part_mbr_table *table;
270 if (gpp->gpp_codesize != MBRSIZE)
273 table = (struct g_part_mbr_table *)basetable;
274 dsn = *(uint32_t *)(table->mbr + DOSDSNOFF);
275 bcopy(gpp->gpp_codeptr, table->mbr, DOSPARTOFF);
277 *(uint32_t *)(table->mbr + DOSDSNOFF) = dsn;
282 g_part_mbr_create(struct g_part_table *basetable, struct g_part_parms *gpp)
284 struct g_provider *pp;
285 struct g_part_mbr_table *table;
287 pp = gpp->gpp_provider;
288 if (pp->sectorsize < MBRSIZE)
291 basetable->gpt_first = basetable->gpt_sectors;
292 basetable->gpt_last = MIN(pp->mediasize / pp->sectorsize,
295 table = (struct g_part_mbr_table *)basetable;
296 le16enc(table->mbr + DOSMAGICOFFSET, DOSMAGIC);
301 g_part_mbr_destroy(struct g_part_table *basetable, struct g_part_parms *gpp)
304 /* Wipe the first sector to clear the partitioning. */
305 basetable->gpt_smhead |= 1;
310 g_part_mbr_dumpconf(struct g_part_table *basetable, struct g_part_entry *baseentry,
311 struct sbuf *sb, const char *indent)
313 struct g_part_mbr_entry *entry;
314 struct g_part_mbr_table *table;
317 table = (struct g_part_mbr_table *)basetable;
318 entry = (struct g_part_mbr_entry *)baseentry;
319 if (indent == NULL) {
320 /* conftxt: libdisk compatibility */
321 sbuf_printf(sb, " xs MBR xt %u", entry->ent.dp_typ);
322 } else if (entry != NULL) {
323 /* confxml: partition entry information */
324 sbuf_printf(sb, "%s<rawtype>%u</rawtype>\n", indent,
326 if (entry->ent.dp_flag & 0x80)
327 sbuf_printf(sb, "%s<attrib>active</attrib>\n", indent);
328 dsn = le32dec(table->mbr + DOSDSNOFF);
329 sbuf_printf(sb, "%s<efimedia>HD(%d,MBR,%#08x,%#jx,%#jx)", indent,
330 entry->base.gpe_index, dsn, (intmax_t)entry->base.gpe_start,
331 (intmax_t)(entry->base.gpe_end - entry->base.gpe_start + 1));
332 sbuf_printf(sb, "</efimedia>\n");
334 /* confxml: scheme information */
339 g_part_mbr_dumpto(struct g_part_table *table, struct g_part_entry *baseentry)
341 struct g_part_mbr_entry *entry;
343 /* Allow dumping to a FreeBSD partition or Linux swap partition only. */
344 entry = (struct g_part_mbr_entry *)baseentry;
345 return ((entry->ent.dp_typ == DOSPTYP_386BSD ||
346 entry->ent.dp_typ == DOSPTYP_LINSWP) ? 1 : 0);
350 g_part_mbr_modify(struct g_part_table *basetable,
351 struct g_part_entry *baseentry, struct g_part_parms *gpp)
353 struct g_part_mbr_entry *entry;
355 if (gpp->gpp_parms & G_PART_PARM_LABEL)
358 entry = (struct g_part_mbr_entry *)baseentry;
359 if (gpp->gpp_parms & G_PART_PARM_TYPE)
360 return (mbr_parse_type(gpp->gpp_type, &entry->ent.dp_typ));
365 g_part_mbr_resize(struct g_part_table *basetable,
366 struct g_part_entry *baseentry, struct g_part_parms *gpp)
368 struct g_part_mbr_entry *entry;
369 struct g_provider *pp;
372 if (baseentry == NULL) {
373 pp = LIST_FIRST(&basetable->gpt_gp->consumer)->provider;
374 basetable->gpt_last = MIN(pp->mediasize / pp->sectorsize,
378 size = gpp->gpp_size;
379 if (mbr_align(basetable, NULL, &size) != 0)
381 /* XXX: prevent unexpected shrinking. */
382 pp = baseentry->gpe_pp;
383 if ((g_debugflags & 0x10) == 0 && size < gpp->gpp_size &&
384 pp->mediasize / pp->sectorsize > size)
386 entry = (struct g_part_mbr_entry *)baseentry;
387 baseentry->gpe_end = baseentry->gpe_start + size - 1;
388 entry->ent.dp_size = size;
389 mbr_set_chs(basetable, baseentry->gpe_end, &entry->ent.dp_ecyl,
390 &entry->ent.dp_ehd, &entry->ent.dp_esect);
395 g_part_mbr_name(struct g_part_table *table, struct g_part_entry *baseentry,
396 char *buf, size_t bufsz)
399 snprintf(buf, bufsz, "s%d", baseentry->gpe_index);
404 g_part_mbr_probe(struct g_part_table *table, struct g_consumer *cp)
407 struct g_provider *pp;
409 int error, index, res, sum;
414 /* Sanity-check the provider. */
415 if (pp->sectorsize < MBRSIZE || pp->mediasize < pp->sectorsize)
417 if (pp->sectorsize > 4096)
420 /* We don't nest under an MBR (see EBR instead). */
421 error = g_getattr("PART::scheme", cp, &psn);
422 if (error == 0 && strcmp(psn, g_part_mbr_scheme.name) == 0)
425 /* Check that there's a MBR. */
426 buf = g_read_data(cp, 0L, pp->sectorsize, &error);
430 /* We goto out on mismatch. */
433 magic = le16dec(buf + DOSMAGICOFFSET);
434 if (magic != DOSMAGIC)
437 for (index = 0; index < NDOSPART; index++) {
438 p = buf + DOSPARTOFF + index * DOSPARTSIZE;
439 if (p[0] != 0 && p[0] != 0x80)
444 * If the partition table does not consist of all zeroes,
445 * assume we have a MBR. If it's all zeroes, we could have
446 * a boot sector. For example, a boot sector that doesn't
447 * have boot code -- common on non-i386 hardware. In that
448 * case we check if we have a possible BPB. If so, then we
449 * assume we have a boot sector instead.
452 for (index = 0; index < NDOSPART * DOSPARTSIZE; index++)
453 sum += buf[DOSPARTOFF + index];
454 if (sum != 0 || !mbr_probe_bpb(buf + 0x0b))
455 res = G_PART_PROBE_PRI_NORM;
463 g_part_mbr_read(struct g_part_table *basetable, struct g_consumer *cp)
465 struct dos_partition ent;
466 struct g_provider *pp;
467 struct g_part_mbr_table *table;
468 struct g_part_mbr_entry *entry;
470 off_t chs, msize, first;
471 u_int sectors, heads;
475 table = (struct g_part_mbr_table *)basetable;
476 first = basetable->gpt_sectors;
477 msize = MIN(pp->mediasize / pp->sectorsize, UINT32_MAX);
479 buf = g_read_data(cp, 0L, pp->sectorsize, &error);
483 bcopy(buf, table->mbr, sizeof(table->mbr));
484 for (index = NDOSPART - 1; index >= 0; index--) {
485 p = buf + DOSPARTOFF + index * DOSPARTSIZE;
494 ent.dp_start = le32dec(p + 8);
495 ent.dp_size = le32dec(p + 12);
496 if (ent.dp_typ == 0 || ent.dp_typ == DOSPTYP_PMBR)
498 if (ent.dp_start == 0 || ent.dp_size == 0)
500 sectors = ent.dp_esect & 0x3f;
501 if (sectors > basetable->gpt_sectors &&
502 !basetable->gpt_fixgeom) {
503 g_part_geometry_heads(msize, sectors, &chs, &heads);
505 basetable->gpt_sectors = sectors;
506 basetable->gpt_heads = heads;
509 if (ent.dp_start < first)
510 first = ent.dp_start;
511 entry = (struct g_part_mbr_entry *)g_part_new_entry(basetable,
512 index + 1, ent.dp_start, ent.dp_start + ent.dp_size - 1);
516 basetable->gpt_entries = NDOSPART;
517 basetable->gpt_first = basetable->gpt_sectors;
518 basetable->gpt_last = msize - 1;
520 if (first < basetable->gpt_first)
521 basetable->gpt_first = 1;
528 g_part_mbr_setunset(struct g_part_table *table, struct g_part_entry *baseentry,
529 const char *attrib, unsigned int set)
531 struct g_part_entry *iter;
532 struct g_part_mbr_entry *entry;
535 if (baseentry == NULL)
537 if (strcasecmp(attrib, "active") != 0)
540 /* Only one entry can have the active attribute. */
541 LIST_FOREACH(iter, &table->gpt_entry, gpe_entry) {
542 if (iter->gpe_deleted)
545 entry = (struct g_part_mbr_entry *)iter;
546 if (iter == baseentry) {
547 if (set && (entry->ent.dp_flag & 0x80) == 0) {
548 entry->ent.dp_flag |= 0x80;
550 } else if (!set && (entry->ent.dp_flag & 0x80)) {
551 entry->ent.dp_flag &= ~0x80;
555 if (set && (entry->ent.dp_flag & 0x80)) {
556 entry->ent.dp_flag &= ~0x80;
560 if (changed && !iter->gpe_created)
561 iter->gpe_modified = 1;
567 g_part_mbr_type(struct g_part_table *basetable, struct g_part_entry *baseentry,
568 char *buf, size_t bufsz)
570 struct g_part_mbr_entry *entry;
573 entry = (struct g_part_mbr_entry *)baseentry;
574 for (i = 0; i < nitems(mbr_alias_match); i++) {
575 if (mbr_alias_match[i].typ == entry->ent.dp_typ)
576 return (g_part_alias_name(mbr_alias_match[i].alias));
578 snprintf(buf, bufsz, "!%d", entry->ent.dp_typ);
583 g_part_mbr_write(struct g_part_table *basetable, struct g_consumer *cp)
585 struct g_part_entry *baseentry;
586 struct g_part_mbr_entry *entry;
587 struct g_part_mbr_table *table;
591 table = (struct g_part_mbr_table *)basetable;
592 baseentry = LIST_FIRST(&basetable->gpt_entry);
593 for (index = 1; index <= basetable->gpt_entries; index++) {
594 p = table->mbr + DOSPARTOFF + (index - 1) * DOSPARTSIZE;
595 entry = (baseentry != NULL && index == baseentry->gpe_index)
596 ? (struct g_part_mbr_entry *)baseentry : NULL;
597 if (entry != NULL && !baseentry->gpe_deleted) {
598 p[0] = entry->ent.dp_flag;
599 p[1] = entry->ent.dp_shd;
600 p[2] = entry->ent.dp_ssect;
601 p[3] = entry->ent.dp_scyl;
602 p[4] = entry->ent.dp_typ;
603 p[5] = entry->ent.dp_ehd;
604 p[6] = entry->ent.dp_esect;
605 p[7] = entry->ent.dp_ecyl;
606 le32enc(p + 8, entry->ent.dp_start);
607 le32enc(p + 12, entry->ent.dp_size);
609 bzero(p, DOSPARTSIZE);
612 baseentry = LIST_NEXT(baseentry, gpe_entry);
615 error = g_write_data(cp, 0, table->mbr, cp->provider->sectorsize);