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freebsd/sys/geom/geom_mbr.c
Pawel Jakub Dawidek 857d14cbc9 Protect against recursive slices creation in simlar way as it is done 
in BSD class, ie. if provider below us uses the same metadata, don't
create slices based on the metadata.
This allows to create slices on geoms with rank != 1 without hacks.

Discussed with:	phk
Approved by:	phk
MFC after:	2 weeks
2005-01-20 22:14:05 +00:00

467 lines
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/*-
* Copyright (c) 2002 Poul-Henning Kamp
* Copyright (c) 2002 Networks Associates Technology, Inc.
* All rights reserved.
*
* This software was developed for the FreeBSD Project by Poul-Henning Kamp
* and NAI Labs, the Security Research Division of Network Associates, Inc.
* under DARPA/SPAWAR contract N66001-01-C-8035 ("CBOSS"), as part of the
* DARPA CHATS research program.
*
* 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 AND CONTRIBUTORS ``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 OR CONTRIBUTORS 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/errno.h>
#include <sys/endian.h>
#include <sys/systm.h>
#include <sys/kernel.h>
#include <sys/fcntl.h>
#include <sys/malloc.h>
#include <sys/bio.h>
#include <sys/lock.h>
#include <sys/mutex.h>
#include <sys/md5.h>
#include <sys/diskmbr.h>
#include <sys/sbuf.h>
#include <geom/geom.h>
#include <geom/geom_slice.h>
#define MBR_CLASS_NAME "MBR"
#define MBREXT_CLASS_NAME "MBREXT"
static struct dos_partition historical_bogus_partition_table[NDOSPART] = {
{ 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, },
{ 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, },
{ 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, },
{ 0x80, 0, 1, 0, DOSPTYP_386BSD, 255, 255, 255, 0, 50000, },
};
static struct dos_partition historical_bogus_partition_table_fixed[NDOSPART] = {
{ 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, },
{ 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, },
{ 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, },
{ 0x80, 0, 1, 0, DOSPTYP_386BSD, 254, 255, 255, 0, 50000, },
};
static void
g_mbr_print(int i, struct dos_partition *dp)
{
printf("[%d] f:%02x typ:%d", i, dp->dp_flag, dp->dp_typ);
printf(" s(CHS):%d/%d/%d", DPCYL(dp->dp_scyl, dp->dp_ssect),
dp->dp_shd, DPSECT(dp->dp_ssect));
printf(" e(CHS):%d/%d/%d", DPCYL(dp->dp_ecyl, dp->dp_esect),
dp->dp_ehd, DPSECT(dp->dp_esect));
printf(" s:%d l:%d\n", dp->dp_start, dp->dp_size);
}
struct g_mbr_softc {
int type [NDOSPART];
u_int sectorsize;
u_char sec0[512];
u_char slicesum[16];
};
static int
g_mbr_modify(struct g_geom *gp, struct g_mbr_softc *ms, u_char *sec0)
{
int i, error;
off_t l[NDOSPART];
struct dos_partition ndp[NDOSPART], *dp;
MD5_CTX md5sum;
g_topology_assert();
if (sec0[0x1fe] != 0x55 && sec0[0x1ff] != 0xaa)
return (EBUSY);
dp = ndp;
for (i = 0; i < NDOSPART; i++) {
dos_partition_dec(
sec0 + DOSPARTOFF + i * sizeof(struct dos_partition),
dp + i);
if (0 && bootverbose)
g_mbr_print(i, dp + i);
}
if ((!bcmp(dp, historical_bogus_partition_table,
sizeof historical_bogus_partition_table)) ||
(!bcmp(dp, historical_bogus_partition_table_fixed,
sizeof historical_bogus_partition_table_fixed))) {
/*
* We will not allow people to write these from "the inside",
* Since properly selfdestructing takes too much code. If
* people really want to do this, they cannot have any
* providers of this geom open, and in that case they can just
* as easily overwrite the MBR in the parent device.
*/
return(EBUSY);
}
for (i = 0; i < NDOSPART; i++) {
/*
* A Protective MBR (PMBR) has a single partition of
* type 0xEE spanning the whole disk. Such a MBR
* protects a GPT on the disk from MBR tools that
* don't know anything about GPT. We're interpreting
* it a bit more loosely: any partition of type 0xEE
* is to be skipped as it doesn't contain any data
* that we should care about. We still allow other
* partitions to be present in the MBR. A PMBR will
* be handled correctly anyway.
*/
if (dp[i].dp_typ == DOSPTYP_PMBR)
l[i] = 0;
else if (dp[i].dp_flag != 0 && dp[i].dp_flag != 0x80)
l[i] = 0;
else if (dp[i].dp_typ == 0)
l[i] = 0;
else
l[i] = (off_t)dp[i].dp_size * ms->sectorsize;
error = g_slice_config(gp, i, G_SLICE_CONFIG_CHECK,
(off_t)dp[i].dp_start * ms->sectorsize, l[i],
ms->sectorsize, "%ss%d", gp->name, 1 + i);
if (error)
return (error);
}
for (i = 0; i < NDOSPART; i++) {
ms->type[i] = dp[i].dp_typ;
g_slice_config(gp, i, G_SLICE_CONFIG_SET,
(off_t)dp[i].dp_start * ms->sectorsize, l[i],
ms->sectorsize, "%ss%d", gp->name, 1 + i);
}
bcopy(sec0, ms->sec0, 512);
/*
* Calculate MD5 from the first sector and use it for avoiding
* recursive slices creation.
*/
MD5Init(&md5sum);
MD5Update(&md5sum, ms->sec0, sizeof(ms->sec0));
MD5Final(ms->slicesum, &md5sum);
return (0);
}
static int
g_mbr_ioctl(struct g_provider *pp, u_long cmd, void *data, int fflag, struct thread *td)
{
struct g_geom *gp;
struct g_mbr_softc *ms;
struct g_slicer *gsp;
struct g_consumer *cp;
int error, opened;
gp = pp->geom;
gsp = gp->softc;
ms = gsp->softc;
opened = 0;
error = 0;
switch(cmd) {
case DIOCSMBR: {
if (!(fflag & FWRITE))
return (EPERM);
DROP_GIANT();
g_topology_lock();
cp = LIST_FIRST(&gp->consumer);
if (cp->acw == 0) {
error = g_access(cp, 0, 1, 0);
if (error == 0)
opened = 1;
}
if (!error)
error = g_mbr_modify(gp, ms, data);
if (!error)
error = g_write_data(cp, 0, data, 512);
if (opened)
g_access(cp, 0, -1 , 0);
g_topology_unlock();
PICKUP_GIANT();
return(error);
}
default:
return (ENOIOCTL);
}
}
static int
g_mbr_start(struct bio *bp)
{
struct g_provider *pp;
struct g_geom *gp;
struct g_mbr_softc *mp;
struct g_slicer *gsp;
int idx;
pp = bp->bio_to;
idx = pp->index;
gp = pp->geom;
gsp = gp->softc;
mp = gsp->softc;
if (bp->bio_cmd == BIO_GETATTR) {
if (g_handleattr_int(bp, "MBR::type", mp->type[idx]))
return (1);
if (g_handleattr_off_t(bp, "MBR::offset",
gsp->slices[idx].offset))
return (1);
if (g_handleattr(bp, "MBR::slicesum", mp->slicesum,
sizeof(mp->slicesum)))
return (1);
}
return (0);
}
static void
g_mbr_dumpconf(struct sbuf *sb, const char *indent, struct g_geom *gp, struct g_consumer *cp __unused, struct g_provider *pp)
{
struct g_mbr_softc *mp;
struct g_slicer *gsp;
gsp = gp->softc;
mp = gsp->softc;
g_slice_dumpconf(sb, indent, gp, cp, pp);
if (pp != NULL) {
if (indent == NULL)
sbuf_printf(sb, " ty %d", mp->type[pp->index]);
else
sbuf_printf(sb, "%s<type>%d</type>\n", indent,
mp->type[pp->index]);
}
}
static struct g_geom *
g_mbr_taste(struct g_class *mp, struct g_provider *pp, int insist)
{
struct g_geom *gp;
struct g_consumer *cp;
int error;
struct g_mbr_softc *ms;
u_int fwsectors, sectorsize;
u_char *buf;
u_char hash[16];
MD5_CTX md5sum;
g_trace(G_T_TOPOLOGY, "mbr_taste(%s,%s)", mp->name, pp->name);
g_topology_assert();
gp = g_slice_new(mp, NDOSPART, pp, &cp, &ms, sizeof *ms, g_mbr_start);
if (gp == NULL)
return (NULL);
g_topology_unlock();
do {
error = g_getattr("GEOM::fwsectors", cp, &fwsectors);
if (error)
fwsectors = 17;
sectorsize = cp->provider->sectorsize;
if (sectorsize < 512)
break;
ms->sectorsize = sectorsize;
buf = g_read_data(cp, 0, sectorsize, &error);
if (buf == NULL || error != 0)
break;
/*
* Calculate MD5 from the first sector and use it for avoiding
* recursive slices creation.
*/
bcopy(buf, ms->sec0, 512);
MD5Init(&md5sum);
MD5Update(&md5sum, ms->sec0, sizeof(ms->sec0));
MD5Final(ms->slicesum, &md5sum);
error = g_getattr("MBR::slicesum", cp, &hash);
if (!error && !bcmp(ms->slicesum, hash, sizeof(hash))) {
g_free(buf);
break;
}
g_topology_lock();
g_mbr_modify(gp, ms, buf);
g_topology_unlock();
g_free(buf);
break;
} while (0);
g_topology_lock();
g_access(cp, -1, 0, 0);
if (LIST_EMPTY(&gp->provider)) {
g_slice_spoiled(cp);
return (NULL);
}
return (gp);
}
static struct g_class g_mbr_class = {
.name = MBR_CLASS_NAME,
.version = G_VERSION,
.taste = g_mbr_taste,
.dumpconf = g_mbr_dumpconf,
.ioctl = g_mbr_ioctl,
};
DECLARE_GEOM_CLASS(g_mbr_class, g_mbr);
#define NDOSEXTPART 32
struct g_mbrext_softc {
int type [NDOSEXTPART];
};
static int
g_mbrext_start(struct bio *bp)
{
struct g_provider *pp;
struct g_geom *gp;
struct g_mbrext_softc *mp;
struct g_slicer *gsp;
int idx;
pp = bp->bio_to;
idx = pp->index;
gp = pp->geom;
gsp = gp->softc;
mp = gsp->softc;
if (bp->bio_cmd == BIO_GETATTR) {
if (g_handleattr_int(bp, "MBR::type", mp->type[idx]))
return (1);
}
return (0);
}
static void
g_mbrext_dumpconf(struct sbuf *sb, const char *indent, struct g_geom *gp, struct g_consumer *cp __unused, struct g_provider *pp)
{
struct g_mbrext_softc *mp;
struct g_slicer *gsp;
g_slice_dumpconf(sb, indent, gp, cp, pp);
gsp = gp->softc;
mp = gsp->softc;
if (pp != NULL) {
if (indent == NULL)
sbuf_printf(sb, " ty %d", mp->type[pp->index]);
else
sbuf_printf(sb, "%s<type>%d</type>\n", indent,
mp->type[pp->index]);
}
}
static struct g_geom *
g_mbrext_taste(struct g_class *mp, struct g_provider *pp, int insist __unused)
{
struct g_geom *gp;
struct g_consumer *cp;
int error, i, slice;
struct g_mbrext_softc *ms;
off_t off;
u_char *buf;
struct dos_partition dp[4];
u_int fwsectors, sectorsize;
g_trace(G_T_TOPOLOGY, "g_mbrext_taste(%s,%s)", mp->name, pp->name);
g_topology_assert();
if (strcmp(pp->geom->class->name, MBR_CLASS_NAME))
return (NULL);
gp = g_slice_new(mp, NDOSEXTPART, pp, &cp, &ms, sizeof *ms,
g_mbrext_start);
if (gp == NULL)
return (NULL);
g_topology_unlock();
off = 0;
slice = 0;
do {
error = g_getattr("MBR::type", cp, &i);
if (error || (i != DOSPTYP_EXT && i != DOSPTYP_EXTLBA))
break;
error = g_getattr("GEOM::fwsectors", cp, &fwsectors);
if (error)
fwsectors = 17;
sectorsize = cp->provider->sectorsize;
if (sectorsize != 512)
break;
for (;;) {
buf = g_read_data(cp, off, sectorsize, &error);
if (buf == NULL || error != 0)
break;
if (buf[0x1fe] != 0x55 && buf[0x1ff] != 0xaa) {
g_free(buf);
break;
}
for (i = 0; i < NDOSPART; i++)
dos_partition_dec(
buf + DOSPARTOFF +
i * sizeof(struct dos_partition), dp + i);
g_free(buf);
if (0 && bootverbose) {
printf("MBREXT Slice %d on %s:\n",
slice + 5, gp->name);
g_mbr_print(0, dp);
g_mbr_print(1, dp + 1);
}
if ((dp[0].dp_flag & 0x7f) == 0 &&
dp[0].dp_size != 0 && dp[0].dp_typ != 0) {
g_topology_lock();
g_slice_config(gp, slice, G_SLICE_CONFIG_SET,
(((off_t)dp[0].dp_start) << 9ULL) + off,
((off_t)dp[0].dp_size) << 9ULL,
sectorsize,
"%*.*s%d",
strlen(gp->name) - 1,
strlen(gp->name) - 1,
gp->name,
slice + 5);
g_topology_unlock();
ms->type[slice] = dp[0].dp_typ;
slice++;
}
if (dp[1].dp_flag != 0)
break;
if (dp[1].dp_typ != DOSPTYP_EXT &&
dp[1].dp_typ != DOSPTYP_EXTLBA)
break;
if (dp[1].dp_size == 0)
break;
off = ((off_t)dp[1].dp_start) << 9ULL;
}
break;
} while (0);
g_topology_lock();
g_access(cp, -1, 0, 0);
if (LIST_EMPTY(&gp->provider)) {
g_slice_spoiled(cp);
return (NULL);
}
return (gp);
}
static struct g_class g_mbrext_class = {
.name = MBREXT_CLASS_NAME,
.version = G_VERSION,
.taste = g_mbrext_taste,
.dumpconf = g_mbrext_dumpconf,
};
DECLARE_GEOM_CLASS(g_mbrext_class, g_mbrext);
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