freebsd-dev/sys/geom/part/g_part_mbr.c
Marcel Moolenaar 6154e492ec Sharpen the saw:
o  MBR uses 32-bit block numbers. Limit the scheme to 2^32-1
   blocks when the media is larger.
2009-03-30 00:53:46 +00:00

526 lines
15 KiB
C

/*-
* Copyright (c) 2007, 2008 Marcel Moolenaar
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <sys/param.h>
#include <sys/bio.h>
#include <sys/diskmbr.h>
#include <sys/endian.h>
#include <sys/kernel.h>
#include <sys/kobj.h>
#include <sys/limits.h>
#include <sys/lock.h>
#include <sys/malloc.h>
#include <sys/mutex.h>
#include <sys/queue.h>
#include <sys/sbuf.h>
#include <sys/systm.h>
#include <geom/geom.h>
#include <geom/part/g_part.h>
#include "g_part_if.h"
#define MBRSIZE 512
struct g_part_mbr_table {
struct g_part_table base;
u_char mbr[MBRSIZE];
};
struct g_part_mbr_entry {
struct g_part_entry base;
struct dos_partition ent;
};
static int g_part_mbr_add(struct g_part_table *, struct g_part_entry *,
struct g_part_parms *);
static int g_part_mbr_bootcode(struct g_part_table *, struct g_part_parms *);
static int g_part_mbr_create(struct g_part_table *, struct g_part_parms *);
static int g_part_mbr_destroy(struct g_part_table *, struct g_part_parms *);
static void g_part_mbr_dumpconf(struct g_part_table *, struct g_part_entry *,
struct sbuf *, const char *);
static int g_part_mbr_dumpto(struct g_part_table *, struct g_part_entry *);
static int g_part_mbr_modify(struct g_part_table *, struct g_part_entry *,
struct g_part_parms *);
static const char *g_part_mbr_name(struct g_part_table *, struct g_part_entry *,
char *, size_t);
static int g_part_mbr_probe(struct g_part_table *, struct g_consumer *);
static int g_part_mbr_read(struct g_part_table *, struct g_consumer *);
static int g_part_mbr_setunset(struct g_part_table *, struct g_part_entry *,
const char *, unsigned int);
static const char *g_part_mbr_type(struct g_part_table *, struct g_part_entry *,
char *, size_t);
static int g_part_mbr_write(struct g_part_table *, struct g_consumer *);
static kobj_method_t g_part_mbr_methods[] = {
KOBJMETHOD(g_part_add, g_part_mbr_add),
KOBJMETHOD(g_part_bootcode, g_part_mbr_bootcode),
KOBJMETHOD(g_part_create, g_part_mbr_create),
KOBJMETHOD(g_part_destroy, g_part_mbr_destroy),
KOBJMETHOD(g_part_dumpconf, g_part_mbr_dumpconf),
KOBJMETHOD(g_part_dumpto, g_part_mbr_dumpto),
KOBJMETHOD(g_part_modify, g_part_mbr_modify),
KOBJMETHOD(g_part_name, g_part_mbr_name),
KOBJMETHOD(g_part_probe, g_part_mbr_probe),
KOBJMETHOD(g_part_read, g_part_mbr_read),
KOBJMETHOD(g_part_setunset, g_part_mbr_setunset),
KOBJMETHOD(g_part_type, g_part_mbr_type),
KOBJMETHOD(g_part_write, g_part_mbr_write),
{ 0, 0 }
};
static struct g_part_scheme g_part_mbr_scheme = {
"MBR",
g_part_mbr_methods,
sizeof(struct g_part_mbr_table),
.gps_entrysz = sizeof(struct g_part_mbr_entry),
.gps_minent = NDOSPART,
.gps_maxent = NDOSPART,
.gps_bootcodesz = MBRSIZE,
};
G_PART_SCHEME_DECLARE(g_part_mbr);
static int
mbr_parse_type(const char *type, u_char *dp_typ)
{
const char *alias;
char *endp;
long lt;
if (type[0] == '!') {
lt = strtol(type + 1, &endp, 0);
if (type[1] == '\0' || *endp != '\0' || lt <= 0 || lt >= 256)
return (EINVAL);
*dp_typ = (u_char)lt;
return (0);
}
alias = g_part_alias_name(G_PART_ALIAS_FREEBSD);
if (!strcasecmp(type, alias)) {
*dp_typ = DOSPTYP_386BSD;
return (0);
}
return (EINVAL);
}
static int
mbr_probe_bpb(u_char *bpb)
{
uint16_t secsz;
uint8_t clstsz;
#define PO2(x) ((x & (x - 1)) == 0)
secsz = le16dec(bpb);
if (secsz < 512 || secsz > 4096 || !PO2(secsz))
return (0);
clstsz = bpb[2];
if (clstsz < 1 || clstsz > 128 || !PO2(clstsz))
return (0);
#undef PO2
return (1);
}
static void
mbr_set_chs(struct g_part_table *table, uint32_t lba, u_char *cylp, u_char *hdp,
u_char *secp)
{
uint32_t cyl, hd, sec;
sec = lba % table->gpt_sectors + 1;
lba /= table->gpt_sectors;
hd = lba % table->gpt_heads;
lba /= table->gpt_heads;
cyl = lba;
if (cyl > 1023)
sec = hd = cyl = ~0;
*cylp = cyl & 0xff;
*hdp = hd & 0xff;
*secp = (sec & 0x3f) | ((cyl >> 2) & 0xc0);
}
static int
g_part_mbr_add(struct g_part_table *basetable, struct g_part_entry *baseentry,
struct g_part_parms *gpp)
{
struct g_part_mbr_entry *entry;
struct g_part_mbr_table *table;
uint32_t start, size, sectors;
if (gpp->gpp_parms & G_PART_PARM_LABEL)
return (EINVAL);
sectors = basetable->gpt_sectors;
entry = (struct g_part_mbr_entry *)baseentry;
table = (struct g_part_mbr_table *)basetable;
start = gpp->gpp_start;
size = gpp->gpp_size;
if (size < sectors)
return (EINVAL);
if (start % sectors) {
size = size - sectors + (start % sectors);
start = start - (start % sectors) + sectors;
}
if (size % sectors)
size = size - (size % sectors);
if (size < sectors)
return (EINVAL);
if (baseentry->gpe_deleted)
bzero(&entry->ent, sizeof(entry->ent));
KASSERT(baseentry->gpe_start <= start, (__func__));
KASSERT(baseentry->gpe_end >= start + size - 1, (__func__));
baseentry->gpe_start = start;
baseentry->gpe_end = start + size - 1;
entry->ent.dp_start = start;
entry->ent.dp_size = size;
mbr_set_chs(basetable, baseentry->gpe_start, &entry->ent.dp_scyl,
&entry->ent.dp_shd, &entry->ent.dp_ssect);
mbr_set_chs(basetable, baseentry->gpe_end, &entry->ent.dp_ecyl,
&entry->ent.dp_ehd, &entry->ent.dp_esect);
return (mbr_parse_type(gpp->gpp_type, &entry->ent.dp_typ));
}
static int
g_part_mbr_bootcode(struct g_part_table *basetable, struct g_part_parms *gpp)
{
struct g_part_mbr_table *table;
size_t codesz;
codesz = DOSPARTOFF;
table = (struct g_part_mbr_table *)basetable;
bzero(table->mbr, codesz);
codesz = MIN(codesz, gpp->gpp_codesize);
if (codesz > 0)
bcopy(gpp->gpp_codeptr, table->mbr, codesz);
return (0);
}
static int
g_part_mbr_create(struct g_part_table *basetable, struct g_part_parms *gpp)
{
struct g_consumer *cp;
struct g_provider *pp;
struct g_part_mbr_table *table;
uint32_t msize;
pp = gpp->gpp_provider;
cp = LIST_FIRST(&pp->consumers);
if (pp->sectorsize < MBRSIZE)
return (ENOSPC);
msize = MIN(pp->mediasize / pp->sectorsize, 0xffffffff);
basetable->gpt_first = basetable->gpt_sectors;
basetable->gpt_last = msize - (msize % basetable->gpt_sectors) - 1;
table = (struct g_part_mbr_table *)basetable;
le16enc(table->mbr + DOSMAGICOFFSET, DOSMAGIC);
return (0);
}
static int
g_part_mbr_destroy(struct g_part_table *basetable, struct g_part_parms *gpp)
{
/* Wipe the first sector to clear the partitioning. */
basetable->gpt_smhead |= 1;
return (0);
}
static void
g_part_mbr_dumpconf(struct g_part_table *table, struct g_part_entry *baseentry,
struct sbuf *sb, const char *indent)
{
struct g_part_mbr_entry *entry;
entry = (struct g_part_mbr_entry *)baseentry;
if (indent == NULL) {
/* conftxt: libdisk compatibility */
sbuf_printf(sb, " xs MBR xt %u", entry->ent.dp_typ);
} else if (entry != NULL) {
/* confxml: partition entry information */
sbuf_printf(sb, "%s<rawtype>%u</rawtype>\n", indent,
entry->ent.dp_typ);
if (entry->ent.dp_flag & 0x80)
sbuf_printf(sb, "%s<attrib>active</attrib>\n", indent);
} else {
/* confxml: scheme information */
}
}
static int
g_part_mbr_dumpto(struct g_part_table *table, struct g_part_entry *baseentry)
{
struct g_part_mbr_entry *entry;
/* Allow dumping to a FreeBSD partition only. */
entry = (struct g_part_mbr_entry *)baseentry;
return ((entry->ent.dp_typ == DOSPTYP_386BSD) ? 1 : 0);
}
static int
g_part_mbr_modify(struct g_part_table *basetable,
struct g_part_entry *baseentry, struct g_part_parms *gpp)
{
struct g_part_mbr_entry *entry;
if (gpp->gpp_parms & G_PART_PARM_LABEL)
return (EINVAL);
entry = (struct g_part_mbr_entry *)baseentry;
if (gpp->gpp_parms & G_PART_PARM_TYPE)
return (mbr_parse_type(gpp->gpp_type, &entry->ent.dp_typ));
return (0);
}
static const char *
g_part_mbr_name(struct g_part_table *table, struct g_part_entry *baseentry,
char *buf, size_t bufsz)
{
snprintf(buf, bufsz, "s%d", baseentry->gpe_index);
return (buf);
}
static int
g_part_mbr_probe(struct g_part_table *table, struct g_consumer *cp)
{
char psn[8];
struct g_provider *pp;
u_char *buf, *p;
int error, index, res, sum;
uint16_t magic;
pp = cp->provider;
/* Sanity-check the provider. */
if (pp->sectorsize < MBRSIZE || pp->mediasize < pp->sectorsize)
return (ENOSPC);
if (pp->sectorsize > 4096)
return (ENXIO);
/* We don't nest under an MBR (see EBR instead). */
error = g_getattr("PART::scheme", cp, &psn);
if (error == 0 && strcmp(psn, g_part_mbr_scheme.name) == 0)
return (ELOOP);
/* Check that there's a MBR. */
buf = g_read_data(cp, 0L, pp->sectorsize, &error);
if (buf == NULL)
return (error);
/* We goto out on mismatch. */
res = ENXIO;
magic = le16dec(buf + DOSMAGICOFFSET);
if (magic != DOSMAGIC)
goto out;
for (index = 0; index < NDOSPART; index++) {
p = buf + DOSPARTOFF + index * DOSPARTSIZE;
if (p[0] != 0 && p[0] != 0x80)
goto out;
}
/*
* If the partition table does not consist of all zeroes,
* assume we have a MBR. If it's all zeroes, we could have
* a boot sector. For example, a boot sector that doesn't
* have boot code -- common on non-i386 hardware. In that
* case we check if we have a possible BPB. If so, then we
* assume we have a boot sector instead.
*/
sum = 0;
for (index = 0; index < NDOSPART * DOSPARTSIZE; index++)
sum += buf[DOSPARTOFF + index];
if (sum != 0 || !mbr_probe_bpb(buf + 0x0b))
res = G_PART_PROBE_PRI_NORM;
out:
g_free(buf);
return (res);
}
static int
g_part_mbr_read(struct g_part_table *basetable, struct g_consumer *cp)
{
struct dos_partition ent;
struct g_provider *pp;
struct g_part_mbr_table *table;
struct g_part_mbr_entry *entry;
u_char *buf, *p;
off_t chs, msize;
u_int sectors, heads;
int error, index;
pp = cp->provider;
table = (struct g_part_mbr_table *)basetable;
msize = pp->mediasize / pp->sectorsize;
buf = g_read_data(cp, 0L, pp->sectorsize, &error);
if (buf == NULL)
return (error);
bcopy(buf, table->mbr, sizeof(table->mbr));
for (index = NDOSPART - 1; index >= 0; index--) {
p = buf + DOSPARTOFF + index * DOSPARTSIZE;
ent.dp_flag = p[0];
ent.dp_shd = p[1];
ent.dp_ssect = p[2];
ent.dp_scyl = p[3];
ent.dp_typ = p[4];
ent.dp_ehd = p[5];
ent.dp_esect = p[6];
ent.dp_ecyl = p[7];
ent.dp_start = le32dec(p + 8);
ent.dp_size = le32dec(p + 12);
if (ent.dp_typ == 0 || ent.dp_typ == DOSPTYP_PMBR)
continue;
if (ent.dp_start == 0 || ent.dp_size == 0)
continue;
sectors = ent.dp_esect & 0x3f;
if (sectors > basetable->gpt_sectors &&
!basetable->gpt_fixgeom) {
g_part_geometry_heads(msize, sectors, &chs, &heads);
if (chs != 0) {
basetable->gpt_sectors = sectors;
basetable->gpt_heads = heads;
}
}
if ((ent.dp_start % basetable->gpt_sectors) != 0)
printf("GEOM: %s: partition %d does not start on a "
"track boundary.\n", pp->name, index + 1);
if ((ent.dp_size % basetable->gpt_sectors) != 0)
printf("GEOM: %s: partition %d does not end on a "
"track boundary.\n", pp->name, index + 1);
entry = (struct g_part_mbr_entry *)g_part_new_entry(basetable,
index + 1, ent.dp_start, ent.dp_start + ent.dp_size - 1);
entry->ent = ent;
}
basetable->gpt_entries = NDOSPART;
basetable->gpt_first = basetable->gpt_sectors;
basetable->gpt_last = msize - (msize % basetable->gpt_sectors) - 1;
return (0);
}
static int
g_part_mbr_setunset(struct g_part_table *table, struct g_part_entry *baseentry,
const char *attrib, unsigned int set)
{
struct g_part_entry *iter;
struct g_part_mbr_entry *entry;
int changed;
if (strcasecmp(attrib, "active") != 0)
return (EINVAL);
/* Only one entry can have the active attribute. */
LIST_FOREACH(iter, &table->gpt_entry, gpe_entry) {
if (iter->gpe_deleted)
continue;
changed = 0;
entry = (struct g_part_mbr_entry *)iter;
if (iter == baseentry) {
if (set && (entry->ent.dp_flag & 0x80) == 0) {
entry->ent.dp_flag |= 0x80;
changed = 1;
} else if (!set && (entry->ent.dp_flag & 0x80)) {
entry->ent.dp_flag &= ~0x80;
changed = 1;
}
} else {
if (set && (entry->ent.dp_flag & 0x80)) {
entry->ent.dp_flag &= ~0x80;
changed = 1;
}
}
if (changed && !iter->gpe_created)
iter->gpe_modified = 1;
}
return (0);
}
static const char *
g_part_mbr_type(struct g_part_table *basetable, struct g_part_entry *baseentry,
char *buf, size_t bufsz)
{
struct g_part_mbr_entry *entry;
int type;
entry = (struct g_part_mbr_entry *)baseentry;
type = entry->ent.dp_typ;
if (type == DOSPTYP_386BSD)
return (g_part_alias_name(G_PART_ALIAS_FREEBSD));
snprintf(buf, bufsz, "!%d", type);
return (buf);
}
static int
g_part_mbr_write(struct g_part_table *basetable, struct g_consumer *cp)
{
struct g_part_entry *baseentry;
struct g_part_mbr_entry *entry;
struct g_part_mbr_table *table;
u_char *p;
int error, index;
table = (struct g_part_mbr_table *)basetable;
baseentry = LIST_FIRST(&basetable->gpt_entry);
for (index = 1; index <= basetable->gpt_entries; index++) {
p = table->mbr + DOSPARTOFF + (index - 1) * DOSPARTSIZE;
entry = (baseentry != NULL && index == baseentry->gpe_index)
? (struct g_part_mbr_entry *)baseentry : NULL;
if (entry != NULL && !baseentry->gpe_deleted) {
p[0] = entry->ent.dp_flag;
p[1] = entry->ent.dp_shd;
p[2] = entry->ent.dp_ssect;
p[3] = entry->ent.dp_scyl;
p[4] = entry->ent.dp_typ;
p[5] = entry->ent.dp_ehd;
p[6] = entry->ent.dp_esect;
p[7] = entry->ent.dp_ecyl;
le32enc(p + 8, entry->ent.dp_start);
le32enc(p + 12, entry->ent.dp_size);
} else
bzero(p, DOSPARTSIZE);
if (entry != NULL)
baseentry = LIST_NEXT(baseentry, gpe_entry);
}
error = g_write_data(cp, 0, table->mbr, cp->provider->sectorsize);
return (error);
}