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,
56 CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
57 "GEOM_PART_MBR Master Boot Record");
59 static u_int enforce_chs = 0;
60 SYSCTL_UINT(_kern_geom_part_mbr, OID_AUTO, enforce_chs,
61 CTLFLAG_RWTUN, &enforce_chs, 0, "Enforce alignment to CHS addressing");
65 struct g_part_mbr_table {
66 struct g_part_table base;
70 struct g_part_mbr_entry {
71 struct g_part_entry base;
72 struct dos_partition ent;
75 static int g_part_mbr_add(struct g_part_table *, struct g_part_entry *,
76 struct g_part_parms *);
77 static int g_part_mbr_bootcode(struct g_part_table *, struct g_part_parms *);
78 static int g_part_mbr_create(struct g_part_table *, struct g_part_parms *);
79 static int g_part_mbr_destroy(struct g_part_table *, struct g_part_parms *);
80 static void g_part_mbr_dumpconf(struct g_part_table *, struct g_part_entry *,
81 struct sbuf *, const char *);
82 static int g_part_mbr_dumpto(struct g_part_table *, struct g_part_entry *);
83 static int g_part_mbr_modify(struct g_part_table *, struct g_part_entry *,
84 struct g_part_parms *);
85 static const char *g_part_mbr_name(struct g_part_table *, struct g_part_entry *,
87 static int g_part_mbr_probe(struct g_part_table *, struct g_consumer *);
88 static int g_part_mbr_read(struct g_part_table *, struct g_consumer *);
89 static int g_part_mbr_setunset(struct g_part_table *, struct g_part_entry *,
90 const char *, unsigned int);
91 static const char *g_part_mbr_type(struct g_part_table *, struct g_part_entry *,
93 static int g_part_mbr_write(struct g_part_table *, struct g_consumer *);
94 static int g_part_mbr_resize(struct g_part_table *, struct g_part_entry *,
95 struct g_part_parms *);
97 static kobj_method_t g_part_mbr_methods[] = {
98 KOBJMETHOD(g_part_add, g_part_mbr_add),
99 KOBJMETHOD(g_part_bootcode, g_part_mbr_bootcode),
100 KOBJMETHOD(g_part_create, g_part_mbr_create),
101 KOBJMETHOD(g_part_destroy, g_part_mbr_destroy),
102 KOBJMETHOD(g_part_dumpconf, g_part_mbr_dumpconf),
103 KOBJMETHOD(g_part_dumpto, g_part_mbr_dumpto),
104 KOBJMETHOD(g_part_modify, g_part_mbr_modify),
105 KOBJMETHOD(g_part_resize, g_part_mbr_resize),
106 KOBJMETHOD(g_part_name, g_part_mbr_name),
107 KOBJMETHOD(g_part_probe, g_part_mbr_probe),
108 KOBJMETHOD(g_part_read, g_part_mbr_read),
109 KOBJMETHOD(g_part_setunset, g_part_mbr_setunset),
110 KOBJMETHOD(g_part_type, g_part_mbr_type),
111 KOBJMETHOD(g_part_write, g_part_mbr_write),
115 static struct g_part_scheme g_part_mbr_scheme = {
118 sizeof(struct g_part_mbr_table),
119 .gps_entrysz = sizeof(struct g_part_mbr_entry),
120 .gps_minent = NDOSPART,
121 .gps_maxent = NDOSPART,
122 .gps_bootcodesz = MBRSIZE,
124 G_PART_SCHEME_DECLARE(g_part_mbr);
125 MODULE_VERSION(geom_part_mbr, 0);
127 static struct g_part_mbr_alias {
130 } mbr_alias_match[] = {
131 { DOSPTYP_386BSD, G_PART_ALIAS_FREEBSD },
132 { DOSPTYP_APPLE_BOOT, G_PART_ALIAS_APPLE_BOOT },
133 { DOSPTYP_APPLE_UFS, G_PART_ALIAS_APPLE_UFS },
134 { DOSPTYP_EFI, G_PART_ALIAS_EFI },
135 { DOSPTYP_EXT, G_PART_ALIAS_EBR },
136 { DOSPTYP_EXTLBA, G_PART_ALIAS_EBR },
137 { DOSPTYP_FAT16, G_PART_ALIAS_MS_FAT16 },
138 { DOSPTYP_FAT32, G_PART_ALIAS_MS_FAT32 },
139 { DOSPTYP_FAT32LBA, G_PART_ALIAS_MS_FAT32LBA },
140 { DOSPTYP_HFS, G_PART_ALIAS_APPLE_HFS },
141 { DOSPTYP_LDM, G_PART_ALIAS_MS_LDM_DATA },
142 { DOSPTYP_LINLVM, G_PART_ALIAS_LINUX_LVM },
143 { DOSPTYP_LINRAID, G_PART_ALIAS_LINUX_RAID },
144 { DOSPTYP_LINSWP, G_PART_ALIAS_LINUX_SWAP },
145 { DOSPTYP_LINUX, G_PART_ALIAS_LINUX_DATA },
146 { DOSPTYP_NTFS, G_PART_ALIAS_MS_NTFS },
147 { DOSPTYP_PPCBOOT, G_PART_ALIAS_PREP_BOOT },
148 { DOSPTYP_VMFS, G_PART_ALIAS_VMFS },
149 { DOSPTYP_VMKDIAG, G_PART_ALIAS_VMKDIAG },
153 mbr_parse_type(const char *type, u_char *dp_typ)
160 if (type[0] == '!') {
161 lt = strtol(type + 1, &endp, 0);
162 if (type[1] == '\0' || *endp != '\0' || lt <= 0 || lt >= 256)
164 *dp_typ = (u_char)lt;
167 for (i = 0; i < nitems(mbr_alias_match); i++) {
168 alias = g_part_alias_name(mbr_alias_match[i].alias);
169 if (strcasecmp(type, alias) == 0) {
170 *dp_typ = mbr_alias_match[i].typ;
178 mbr_probe_bpb(u_char *bpb)
183 #define PO2(x) ((x & (x - 1)) == 0)
184 secsz = le16dec(bpb);
185 if (secsz < 512 || secsz > 4096 || !PO2(secsz))
188 if (clstsz < 1 || clstsz > 128 || !PO2(clstsz))
196 mbr_set_chs(struct g_part_table *table, uint32_t lba, u_char *cylp, u_char *hdp,
199 uint32_t cyl, hd, sec;
201 sec = lba % table->gpt_sectors + 1;
202 lba /= table->gpt_sectors;
203 hd = lba % table->gpt_heads;
204 lba /= table->gpt_heads;
211 *secp = (sec & 0x3f) | ((cyl >> 2) & 0xc0);
215 mbr_align(struct g_part_table *basetable, uint32_t *start, uint32_t *size)
219 if (enforce_chs == 0)
221 sectors = basetable->gpt_sectors;
224 if (start != NULL && (*start % sectors)) {
225 *size += (*start % sectors) - sectors;
226 *start -= (*start % sectors) - sectors;
229 *size -= (*size % sectors);
236 g_part_mbr_add(struct g_part_table *basetable, struct g_part_entry *baseentry,
237 struct g_part_parms *gpp)
239 struct g_part_mbr_entry *entry;
240 uint32_t start, size;
242 if (gpp->gpp_parms & G_PART_PARM_LABEL)
245 entry = (struct g_part_mbr_entry *)baseentry;
246 start = gpp->gpp_start;
247 size = gpp->gpp_size;
248 if (mbr_align(basetable, &start, &size) != 0)
250 if (baseentry->gpe_deleted)
251 bzero(&entry->ent, sizeof(entry->ent));
253 KASSERT(baseentry->gpe_start <= start, ("%s", __func__));
254 KASSERT(baseentry->gpe_end >= start + size - 1, ("%s", __func__));
255 baseentry->gpe_start = start;
256 baseentry->gpe_end = start + size - 1;
257 entry->ent.dp_start = start;
258 entry->ent.dp_size = size;
259 mbr_set_chs(basetable, baseentry->gpe_start, &entry->ent.dp_scyl,
260 &entry->ent.dp_shd, &entry->ent.dp_ssect);
261 mbr_set_chs(basetable, baseentry->gpe_end, &entry->ent.dp_ecyl,
262 &entry->ent.dp_ehd, &entry->ent.dp_esect);
263 return (mbr_parse_type(gpp->gpp_type, &entry->ent.dp_typ));
267 g_part_mbr_bootcode(struct g_part_table *basetable, struct g_part_parms *gpp)
269 struct g_part_mbr_table *table;
272 if (gpp->gpp_codesize != MBRSIZE)
275 table = (struct g_part_mbr_table *)basetable;
276 dsn = *(uint32_t *)(table->mbr + DOSDSNOFF);
277 bcopy(gpp->gpp_codeptr, table->mbr, DOSPARTOFF);
278 if (dsn != 0 && !gpp->gpp_skip_dsn)
279 *(uint32_t *)(table->mbr + DOSDSNOFF) = dsn;
284 g_part_mbr_create(struct g_part_table *basetable, struct g_part_parms *gpp)
286 struct g_provider *pp;
287 struct g_part_mbr_table *table;
289 pp = gpp->gpp_provider;
290 if (pp->sectorsize < MBRSIZE)
293 basetable->gpt_first = basetable->gpt_sectors;
294 basetable->gpt_last = MIN(pp->mediasize / pp->sectorsize,
297 table = (struct g_part_mbr_table *)basetable;
298 le16enc(table->mbr + DOSMAGICOFFSET, DOSMAGIC);
303 g_part_mbr_destroy(struct g_part_table *basetable, struct g_part_parms *gpp)
306 /* Wipe the first sector to clear the partitioning. */
307 basetable->gpt_smhead |= 1;
312 g_part_mbr_dumpconf(struct g_part_table *basetable, struct g_part_entry *baseentry,
313 struct sbuf *sb, const char *indent)
315 struct g_part_mbr_entry *entry;
316 struct g_part_mbr_table *table;
319 table = (struct g_part_mbr_table *)basetable;
320 entry = (struct g_part_mbr_entry *)baseentry;
321 if (indent == NULL) {
322 /* conftxt: libdisk compatibility */
323 sbuf_printf(sb, " xs MBR xt %u", entry->ent.dp_typ);
324 } else if (entry != NULL) {
325 /* confxml: partition entry information */
326 sbuf_printf(sb, "%s<rawtype>%u</rawtype>\n", indent,
328 if (entry->ent.dp_flag & 0x80)
329 sbuf_printf(sb, "%s<attrib>active</attrib>\n", indent);
330 dsn = le32dec(table->mbr + DOSDSNOFF);
331 sbuf_printf(sb, "%s<efimedia>HD(%d,MBR,%#08x,%#jx,%#jx)", indent,
332 entry->base.gpe_index, dsn, (intmax_t)entry->base.gpe_start,
333 (intmax_t)(entry->base.gpe_end - entry->base.gpe_start + 1));
334 sbuf_cat(sb, "</efimedia>\n");
336 /* confxml: scheme information */
341 g_part_mbr_dumpto(struct g_part_table *table, struct g_part_entry *baseentry)
343 struct g_part_mbr_entry *entry;
345 /* Allow dumping to a FreeBSD partition or Linux swap partition only. */
346 entry = (struct g_part_mbr_entry *)baseentry;
347 return ((entry->ent.dp_typ == DOSPTYP_386BSD ||
348 entry->ent.dp_typ == DOSPTYP_LINSWP) ? 1 : 0);
352 g_part_mbr_modify(struct g_part_table *basetable,
353 struct g_part_entry *baseentry, struct g_part_parms *gpp)
355 struct g_part_mbr_entry *entry;
357 if (gpp->gpp_parms & G_PART_PARM_LABEL)
360 entry = (struct g_part_mbr_entry *)baseentry;
361 if (gpp->gpp_parms & G_PART_PARM_TYPE)
362 return (mbr_parse_type(gpp->gpp_type, &entry->ent.dp_typ));
367 g_part_mbr_resize(struct g_part_table *basetable,
368 struct g_part_entry *baseentry, struct g_part_parms *gpp)
370 struct g_part_mbr_entry *entry;
371 struct g_provider *pp;
374 if (baseentry == NULL) {
375 pp = LIST_FIRST(&basetable->gpt_gp->consumer)->provider;
376 basetable->gpt_last = MIN(pp->mediasize / pp->sectorsize,
380 size = gpp->gpp_size;
381 if (mbr_align(basetable, NULL, &size) != 0)
383 /* XXX: prevent unexpected shrinking. */
384 pp = baseentry->gpe_pp;
385 if ((g_debugflags & G_F_FOOTSHOOTING) == 0 && size < gpp->gpp_size &&
386 pp->mediasize / pp->sectorsize > size)
388 entry = (struct g_part_mbr_entry *)baseentry;
389 baseentry->gpe_end = baseentry->gpe_start + size - 1;
390 entry->ent.dp_size = size;
391 mbr_set_chs(basetable, baseentry->gpe_end, &entry->ent.dp_ecyl,
392 &entry->ent.dp_ehd, &entry->ent.dp_esect);
397 g_part_mbr_name(struct g_part_table *table, struct g_part_entry *baseentry,
398 char *buf, size_t bufsz)
401 snprintf(buf, bufsz, "s%d", baseentry->gpe_index);
406 g_part_mbr_probe(struct g_part_table *table, struct g_consumer *cp)
409 struct g_provider *pp;
411 int error, index, res, sum;
416 /* Sanity-check the provider. */
417 if (pp->sectorsize < MBRSIZE || pp->mediasize < pp->sectorsize)
419 if (pp->sectorsize > 4096)
422 /* We don't nest under an MBR (see EBR instead). */
423 error = g_getattr("PART::scheme", cp, &psn);
424 if (error == 0 && strcmp(psn, g_part_mbr_scheme.name) == 0)
427 /* Check that there's a MBR. */
428 buf = g_read_data(cp, 0L, pp->sectorsize, &error);
432 /* We goto out on mismatch. */
435 magic = le16dec(buf + DOSMAGICOFFSET);
436 if (magic != DOSMAGIC)
439 for (index = 0; index < NDOSPART; index++) {
440 p = buf + DOSPARTOFF + index * DOSPARTSIZE;
441 if (p[0] != 0 && p[0] != 0x80)
446 * If the partition table does not consist of all zeroes,
447 * assume we have a MBR. If it's all zeroes, we could have
448 * a boot sector. For example, a boot sector that doesn't
449 * have boot code -- common on non-i386 hardware. In that
450 * case we check if we have a possible BPB. If so, then we
451 * assume we have a boot sector instead.
454 for (index = 0; index < NDOSPART * DOSPARTSIZE; index++)
455 sum += buf[DOSPARTOFF + index];
456 if (sum != 0 || !mbr_probe_bpb(buf + 0x0b))
457 res = G_PART_PROBE_PRI_NORM;
465 g_part_mbr_read(struct g_part_table *basetable, struct g_consumer *cp)
467 struct dos_partition ent;
468 struct g_provider *pp;
469 struct g_part_mbr_table *table;
470 struct g_part_mbr_entry *entry;
472 off_t chs, msize, first;
473 u_int sectors, heads;
477 table = (struct g_part_mbr_table *)basetable;
478 first = basetable->gpt_sectors;
479 msize = MIN(pp->mediasize / pp->sectorsize, UINT32_MAX);
481 buf = g_read_data(cp, 0L, pp->sectorsize, &error);
485 bcopy(buf, table->mbr, sizeof(table->mbr));
486 for (index = NDOSPART - 1; index >= 0; index--) {
487 p = buf + DOSPARTOFF + index * DOSPARTSIZE;
496 ent.dp_start = le32dec(p + 8);
497 ent.dp_size = le32dec(p + 12);
498 if (ent.dp_typ == 0 || ent.dp_typ == DOSPTYP_PMBR)
500 if (ent.dp_start == 0 || ent.dp_size == 0)
502 sectors = ent.dp_esect & 0x3f;
503 if (sectors > basetable->gpt_sectors &&
504 !basetable->gpt_fixgeom) {
505 g_part_geometry_heads(msize, sectors, &chs, &heads);
507 basetable->gpt_sectors = sectors;
508 basetable->gpt_heads = heads;
511 if (ent.dp_start < first)
512 first = ent.dp_start;
513 entry = (struct g_part_mbr_entry *)g_part_new_entry(basetable,
514 index + 1, ent.dp_start, ent.dp_start + ent.dp_size - 1);
518 basetable->gpt_entries = NDOSPART;
519 basetable->gpt_first = basetable->gpt_sectors;
520 basetable->gpt_last = msize - 1;
522 if (first < basetable->gpt_first)
523 basetable->gpt_first = 1;
530 g_part_mbr_setunset(struct g_part_table *table, struct g_part_entry *baseentry,
531 const char *attrib, unsigned int set)
533 struct g_part_entry *iter;
534 struct g_part_mbr_entry *entry;
537 if (baseentry == NULL)
539 if (strcasecmp(attrib, "active") != 0)
542 /* Only one entry can have the active attribute. */
543 LIST_FOREACH(iter, &table->gpt_entry, gpe_entry) {
544 if (iter->gpe_deleted)
547 entry = (struct g_part_mbr_entry *)iter;
548 if (iter == baseentry) {
549 if (set && (entry->ent.dp_flag & 0x80) == 0) {
550 entry->ent.dp_flag |= 0x80;
552 } else if (!set && (entry->ent.dp_flag & 0x80)) {
553 entry->ent.dp_flag &= ~0x80;
557 if (set && (entry->ent.dp_flag & 0x80)) {
558 entry->ent.dp_flag &= ~0x80;
562 if (changed && !iter->gpe_created)
563 iter->gpe_modified = 1;
569 g_part_mbr_type(struct g_part_table *basetable, struct g_part_entry *baseentry,
570 char *buf, size_t bufsz)
572 struct g_part_mbr_entry *entry;
575 entry = (struct g_part_mbr_entry *)baseentry;
576 for (i = 0; i < nitems(mbr_alias_match); i++) {
577 if (mbr_alias_match[i].typ == entry->ent.dp_typ)
578 return (g_part_alias_name(mbr_alias_match[i].alias));
580 snprintf(buf, bufsz, "!%d", entry->ent.dp_typ);
585 g_part_mbr_write(struct g_part_table *basetable, struct g_consumer *cp)
587 struct g_part_entry *baseentry;
588 struct g_part_mbr_entry *entry;
589 struct g_part_mbr_table *table;
593 table = (struct g_part_mbr_table *)basetable;
594 baseentry = LIST_FIRST(&basetable->gpt_entry);
595 for (index = 1; index <= basetable->gpt_entries; index++) {
596 p = table->mbr + DOSPARTOFF + (index - 1) * DOSPARTSIZE;
597 entry = (baseentry != NULL && index == baseentry->gpe_index)
598 ? (struct g_part_mbr_entry *)baseentry : NULL;
599 if (entry != NULL && !baseentry->gpe_deleted) {
600 p[0] = entry->ent.dp_flag;
601 p[1] = entry->ent.dp_shd;
602 p[2] = entry->ent.dp_ssect;
603 p[3] = entry->ent.dp_scyl;
604 p[4] = entry->ent.dp_typ;
605 p[5] = entry->ent.dp_ehd;
606 p[6] = entry->ent.dp_esect;
607 p[7] = entry->ent.dp_ecyl;
608 le32enc(p + 8, entry->ent.dp_start);
609 le32enc(p + 12, entry->ent.dp_size);
611 bzero(p, DOSPARTSIZE);
614 baseentry = LIST_NEXT(baseentry, gpe_entry);
617 error = g_write_data(cp, 0, table->mbr, cp->provider->sectorsize);