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_EXTLBA, G_PART_ALIAS_EBR },
136 { DOSPTYP_LDM, G_PART_ALIAS_MS_LDM_DATA },
137 { DOSPTYP_LINSWP, G_PART_ALIAS_LINUX_SWAP },
138 { DOSPTYP_LINUX, G_PART_ALIAS_LINUX_DATA },
139 { DOSPTYP_LINLVM, G_PART_ALIAS_LINUX_LVM },
140 { DOSPTYP_LINRAID, G_PART_ALIAS_LINUX_RAID },
141 { DOSPTYP_PPCBOOT, G_PART_ALIAS_PREP_BOOT },
142 { DOSPTYP_VMFS, G_PART_ALIAS_VMFS },
143 { DOSPTYP_VMKDIAG, G_PART_ALIAS_VMKDIAG },
144 { DOSPTYP_APPLE_UFS, G_PART_ALIAS_APPLE_UFS },
145 { DOSPTYP_APPLE_BOOT, G_PART_ALIAS_APPLE_BOOT },
146 { DOSPTYP_HFS, G_PART_ALIAS_APPLE_HFS },
150 mbr_parse_type(const char *type, u_char *dp_typ)
157 if (type[0] == '!') {
158 lt = strtol(type + 1, &endp, 0);
159 if (type[1] == '\0' || *endp != '\0' || lt <= 0 || lt >= 256)
161 *dp_typ = (u_char)lt;
164 for (i = 0; i < nitems(mbr_alias_match); i++) {
165 alias = g_part_alias_name(mbr_alias_match[i].alias);
166 if (strcasecmp(type, alias) == 0) {
167 *dp_typ = mbr_alias_match[i].typ;
175 mbr_probe_bpb(u_char *bpb)
180 #define PO2(x) ((x & (x - 1)) == 0)
181 secsz = le16dec(bpb);
182 if (secsz < 512 || secsz > 4096 || !PO2(secsz))
185 if (clstsz < 1 || clstsz > 128 || !PO2(clstsz))
193 mbr_set_chs(struct g_part_table *table, uint32_t lba, u_char *cylp, u_char *hdp,
196 uint32_t cyl, hd, sec;
198 sec = lba % table->gpt_sectors + 1;
199 lba /= table->gpt_sectors;
200 hd = lba % table->gpt_heads;
201 lba /= table->gpt_heads;
208 *secp = (sec & 0x3f) | ((cyl >> 2) & 0xc0);
212 mbr_align(struct g_part_table *basetable, uint32_t *start, uint32_t *size)
216 if (enforce_chs == 0)
218 sectors = basetable->gpt_sectors;
221 if (start != NULL && (*start % sectors)) {
222 *size += (*start % sectors) - sectors;
223 *start -= (*start % sectors) - sectors;
226 *size -= (*size % sectors);
233 g_part_mbr_add(struct g_part_table *basetable, struct g_part_entry *baseentry,
234 struct g_part_parms *gpp)
236 struct g_part_mbr_entry *entry;
237 uint32_t start, size;
239 if (gpp->gpp_parms & G_PART_PARM_LABEL)
242 entry = (struct g_part_mbr_entry *)baseentry;
243 start = gpp->gpp_start;
244 size = gpp->gpp_size;
245 if (mbr_align(basetable, &start, &size) != 0)
247 if (baseentry->gpe_deleted)
248 bzero(&entry->ent, sizeof(entry->ent));
250 KASSERT(baseentry->gpe_start <= start, ("%s", __func__));
251 KASSERT(baseentry->gpe_end >= start + size - 1, ("%s", __func__));
252 baseentry->gpe_start = start;
253 baseentry->gpe_end = start + size - 1;
254 entry->ent.dp_start = start;
255 entry->ent.dp_size = size;
256 mbr_set_chs(basetable, baseentry->gpe_start, &entry->ent.dp_scyl,
257 &entry->ent.dp_shd, &entry->ent.dp_ssect);
258 mbr_set_chs(basetable, baseentry->gpe_end, &entry->ent.dp_ecyl,
259 &entry->ent.dp_ehd, &entry->ent.dp_esect);
260 return (mbr_parse_type(gpp->gpp_type, &entry->ent.dp_typ));
264 g_part_mbr_bootcode(struct g_part_table *basetable, struct g_part_parms *gpp)
266 struct g_part_mbr_table *table;
269 if (gpp->gpp_codesize != MBRSIZE)
272 table = (struct g_part_mbr_table *)basetable;
273 dsn = *(uint32_t *)(table->mbr + DOSDSNOFF);
274 bcopy(gpp->gpp_codeptr, table->mbr, DOSPARTOFF);
276 *(uint32_t *)(table->mbr + DOSDSNOFF) = dsn;
281 g_part_mbr_create(struct g_part_table *basetable, struct g_part_parms *gpp)
283 struct g_provider *pp;
284 struct g_part_mbr_table *table;
286 pp = gpp->gpp_provider;
287 if (pp->sectorsize < MBRSIZE)
290 basetable->gpt_first = basetable->gpt_sectors;
291 basetable->gpt_last = MIN(pp->mediasize / pp->sectorsize,
294 table = (struct g_part_mbr_table *)basetable;
295 le16enc(table->mbr + DOSMAGICOFFSET, DOSMAGIC);
300 g_part_mbr_destroy(struct g_part_table *basetable, struct g_part_parms *gpp)
303 /* Wipe the first sector to clear the partitioning. */
304 basetable->gpt_smhead |= 1;
309 g_part_mbr_dumpconf(struct g_part_table *basetable, struct g_part_entry *baseentry,
310 struct sbuf *sb, const char *indent)
312 struct g_part_mbr_entry *entry;
313 struct g_part_mbr_table *table;
316 table = (struct g_part_mbr_table *)basetable;
317 entry = (struct g_part_mbr_entry *)baseentry;
318 if (indent == NULL) {
319 /* conftxt: libdisk compatibility */
320 sbuf_printf(sb, " xs MBR xt %u", entry->ent.dp_typ);
321 } else if (entry != NULL) {
322 /* confxml: partition entry information */
323 sbuf_printf(sb, "%s<rawtype>%u</rawtype>\n", indent,
325 if (entry->ent.dp_flag & 0x80)
326 sbuf_printf(sb, "%s<attrib>active</attrib>\n", indent);
327 dsn = le32dec(table->mbr + DOSDSNOFF);
328 sbuf_printf(sb, "%s<efimedia>HD(%d,MBR,%#08x,%#jx,%#jx)", indent,
329 entry->base.gpe_index, dsn, (intmax_t)entry->base.gpe_start,
330 (intmax_t)(entry->base.gpe_end - entry->base.gpe_start + 1));
331 sbuf_printf(sb, "</efimedia>\n");
333 /* confxml: scheme information */
338 g_part_mbr_dumpto(struct g_part_table *table, struct g_part_entry *baseentry)
340 struct g_part_mbr_entry *entry;
342 /* Allow dumping to a FreeBSD partition or Linux swap partition only. */
343 entry = (struct g_part_mbr_entry *)baseentry;
344 return ((entry->ent.dp_typ == DOSPTYP_386BSD ||
345 entry->ent.dp_typ == DOSPTYP_LINSWP) ? 1 : 0);
349 g_part_mbr_modify(struct g_part_table *basetable,
350 struct g_part_entry *baseentry, struct g_part_parms *gpp)
352 struct g_part_mbr_entry *entry;
354 if (gpp->gpp_parms & G_PART_PARM_LABEL)
357 entry = (struct g_part_mbr_entry *)baseentry;
358 if (gpp->gpp_parms & G_PART_PARM_TYPE)
359 return (mbr_parse_type(gpp->gpp_type, &entry->ent.dp_typ));
364 g_part_mbr_resize(struct g_part_table *basetable,
365 struct g_part_entry *baseentry, struct g_part_parms *gpp)
367 struct g_part_mbr_entry *entry;
368 struct g_provider *pp;
371 if (baseentry == NULL) {
372 pp = LIST_FIRST(&basetable->gpt_gp->consumer)->provider;
373 basetable->gpt_last = MIN(pp->mediasize / pp->sectorsize,
377 size = gpp->gpp_size;
378 if (mbr_align(basetable, NULL, &size) != 0)
380 /* XXX: prevent unexpected shrinking. */
381 pp = baseentry->gpe_pp;
382 if ((g_debugflags & 0x10) == 0 && size < gpp->gpp_size &&
383 pp->mediasize / pp->sectorsize > size)
385 entry = (struct g_part_mbr_entry *)baseentry;
386 baseentry->gpe_end = baseentry->gpe_start + size - 1;
387 entry->ent.dp_size = size;
388 mbr_set_chs(basetable, baseentry->gpe_end, &entry->ent.dp_ecyl,
389 &entry->ent.dp_ehd, &entry->ent.dp_esect);
394 g_part_mbr_name(struct g_part_table *table, struct g_part_entry *baseentry,
395 char *buf, size_t bufsz)
398 snprintf(buf, bufsz, "s%d", baseentry->gpe_index);
403 g_part_mbr_probe(struct g_part_table *table, struct g_consumer *cp)
406 struct g_provider *pp;
408 int error, index, res, sum;
413 /* Sanity-check the provider. */
414 if (pp->sectorsize < MBRSIZE || pp->mediasize < pp->sectorsize)
416 if (pp->sectorsize > 4096)
419 /* We don't nest under an MBR (see EBR instead). */
420 error = g_getattr("PART::scheme", cp, &psn);
421 if (error == 0 && strcmp(psn, g_part_mbr_scheme.name) == 0)
424 /* Check that there's a MBR. */
425 buf = g_read_data(cp, 0L, pp->sectorsize, &error);
429 /* We goto out on mismatch. */
432 magic = le16dec(buf + DOSMAGICOFFSET);
433 if (magic != DOSMAGIC)
436 for (index = 0; index < NDOSPART; index++) {
437 p = buf + DOSPARTOFF + index * DOSPARTSIZE;
438 if (p[0] != 0 && p[0] != 0x80)
443 * If the partition table does not consist of all zeroes,
444 * assume we have a MBR. If it's all zeroes, we could have
445 * a boot sector. For example, a boot sector that doesn't
446 * have boot code -- common on non-i386 hardware. In that
447 * case we check if we have a possible BPB. If so, then we
448 * assume we have a boot sector instead.
451 for (index = 0; index < NDOSPART * DOSPARTSIZE; index++)
452 sum += buf[DOSPARTOFF + index];
453 if (sum != 0 || !mbr_probe_bpb(buf + 0x0b))
454 res = G_PART_PROBE_PRI_NORM;
462 g_part_mbr_read(struct g_part_table *basetable, struct g_consumer *cp)
464 struct dos_partition ent;
465 struct g_provider *pp;
466 struct g_part_mbr_table *table;
467 struct g_part_mbr_entry *entry;
469 off_t chs, msize, first;
470 u_int sectors, heads;
474 table = (struct g_part_mbr_table *)basetable;
475 first = basetable->gpt_sectors;
476 msize = MIN(pp->mediasize / pp->sectorsize, UINT32_MAX);
478 buf = g_read_data(cp, 0L, pp->sectorsize, &error);
482 bcopy(buf, table->mbr, sizeof(table->mbr));
483 for (index = NDOSPART - 1; index >= 0; index--) {
484 p = buf + DOSPARTOFF + index * DOSPARTSIZE;
493 ent.dp_start = le32dec(p + 8);
494 ent.dp_size = le32dec(p + 12);
495 if (ent.dp_typ == 0 || ent.dp_typ == DOSPTYP_PMBR)
497 if (ent.dp_start == 0 || ent.dp_size == 0)
499 sectors = ent.dp_esect & 0x3f;
500 if (sectors > basetable->gpt_sectors &&
501 !basetable->gpt_fixgeom) {
502 g_part_geometry_heads(msize, sectors, &chs, &heads);
504 basetable->gpt_sectors = sectors;
505 basetable->gpt_heads = heads;
508 if (ent.dp_start < first)
509 first = ent.dp_start;
510 entry = (struct g_part_mbr_entry *)g_part_new_entry(basetable,
511 index + 1, ent.dp_start, ent.dp_start + ent.dp_size - 1);
515 basetable->gpt_entries = NDOSPART;
516 basetable->gpt_first = basetable->gpt_sectors;
517 basetable->gpt_last = msize - 1;
519 if (first < basetable->gpt_first)
520 basetable->gpt_first = 1;
527 g_part_mbr_setunset(struct g_part_table *table, struct g_part_entry *baseentry,
528 const char *attrib, unsigned int set)
530 struct g_part_entry *iter;
531 struct g_part_mbr_entry *entry;
534 if (baseentry == NULL)
536 if (strcasecmp(attrib, "active") != 0)
539 /* Only one entry can have the active attribute. */
540 LIST_FOREACH(iter, &table->gpt_entry, gpe_entry) {
541 if (iter->gpe_deleted)
544 entry = (struct g_part_mbr_entry *)iter;
545 if (iter == baseentry) {
546 if (set && (entry->ent.dp_flag & 0x80) == 0) {
547 entry->ent.dp_flag |= 0x80;
549 } else if (!set && (entry->ent.dp_flag & 0x80)) {
550 entry->ent.dp_flag &= ~0x80;
554 if (set && (entry->ent.dp_flag & 0x80)) {
555 entry->ent.dp_flag &= ~0x80;
559 if (changed && !iter->gpe_created)
560 iter->gpe_modified = 1;
566 g_part_mbr_type(struct g_part_table *basetable, struct g_part_entry *baseentry,
567 char *buf, size_t bufsz)
569 struct g_part_mbr_entry *entry;
572 entry = (struct g_part_mbr_entry *)baseentry;
573 for (i = 0; i < nitems(mbr_alias_match); i++) {
574 if (mbr_alias_match[i].typ == entry->ent.dp_typ)
575 return (g_part_alias_name(mbr_alias_match[i].alias));
577 snprintf(buf, bufsz, "!%d", entry->ent.dp_typ);
582 g_part_mbr_write(struct g_part_table *basetable, struct g_consumer *cp)
584 struct g_part_entry *baseentry;
585 struct g_part_mbr_entry *entry;
586 struct g_part_mbr_table *table;
590 table = (struct g_part_mbr_table *)basetable;
591 baseentry = LIST_FIRST(&basetable->gpt_entry);
592 for (index = 1; index <= basetable->gpt_entries; index++) {
593 p = table->mbr + DOSPARTOFF + (index - 1) * DOSPARTSIZE;
594 entry = (baseentry != NULL && index == baseentry->gpe_index)
595 ? (struct g_part_mbr_entry *)baseentry : NULL;
596 if (entry != NULL && !baseentry->gpe_deleted) {
597 p[0] = entry->ent.dp_flag;
598 p[1] = entry->ent.dp_shd;
599 p[2] = entry->ent.dp_ssect;
600 p[3] = entry->ent.dp_scyl;
601 p[4] = entry->ent.dp_typ;
602 p[5] = entry->ent.dp_ehd;
603 p[6] = entry->ent.dp_esect;
604 p[7] = entry->ent.dp_ecyl;
605 le32enc(p + 8, entry->ent.dp_start);
606 le32enc(p + 12, entry->ent.dp_size);
608 bzero(p, DOSPARTSIZE);
611 baseentry = LIST_NEXT(baseentry, gpe_entry);
614 error = g_write_data(cp, 0, table->mbr, cp->provider->sectorsize);