freebsd-nq/sys/kern/subr_diskmbr.c
2003-01-03 05:57:35 +00:00

545 lines
16 KiB
C

/*-
* Copyright (c) 1994 Bruce D. Evans.
* All rights reserved.
*
* Copyright (c) 1982, 1986, 1988 Regents of the University of California.
* 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.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the University of
* California, Berkeley and its contributors.
* 4. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS 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 REGENTS 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.
*
* from: @(#)ufs_disksubr.c 7.16 (Berkeley) 5/4/91
* from: ufs_disksubr.c,v 1.8 1994/06/07 01:21:39 phk Exp $
* $FreeBSD$
*/
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/bio.h>
#include <sys/buf.h>
#include <sys/conf.h>
#ifdef PC98
#define PC98_ATCOMPAT
#define dsinit atcompat_dsinit
#endif
#include <sys/disk.h>
#include <sys/disklabel.h>
#include <sys/diskmbr.h>
#define DOSPTYP_EXTENDED 5
#define DOSPTYP_EXTENDEDX 15
#define DOSPTYP_ONTRACK 84
#include <sys/diskslice.h>
#include <sys/malloc.h>
#include <sys/syslog.h>
#define TRACE(str) do { if (dsi_debug) printf str; } while (0)
static volatile u_char dsi_debug;
/*
* This is what we have embedded in every boot1 for supporting the bogus
* "Dangerously Dedicated" mode. However, the old table is broken because
* it has an illegal geometry in it - it specifies 256 heads (heads = end
* head + 1) which causes nasty stuff when that wraps to zero in bios code.
* eg: divide by zero etc. This caused the dead-thinkpad problem, numerous
* SCSI bios crashes, EFI to crash, etc.
*
* We still have to recognize the old table though, even though we stopped
* inflicting it apon the world.
*/
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 int check_part(char *sname, struct dos_partition *dp,
u_long offset, int nsectors, int ntracks,
u_long mbr_offset);
static void mbr_extended(dev_t dev, struct disklabel *lp,
struct diskslices *ssp, u_long ext_offset,
u_long ext_size, u_long base_ext_offset,
int nsectors, int ntracks, u_long mbr_offset,
int level);
static int mbr_setslice(char *sname, struct disklabel *lp,
struct diskslice *sp, struct dos_partition *dp,
u_long br_offset);
static int
check_part(sname, dp, offset, nsectors, ntracks, mbr_offset )
char *sname;
struct dos_partition *dp;
u_long offset;
int nsectors;
int ntracks;
u_long mbr_offset;
{
int chs_ecyl;
int chs_esect;
int chs_scyl;
int chs_ssect;
int error;
u_long esector;
u_long esector1;
u_long secpercyl;
u_long ssector;
u_long ssector1;
secpercyl = (u_long)nsectors * ntracks;
chs_scyl = DPCYL(dp->dp_scyl, dp->dp_ssect);
chs_ssect = DPSECT(dp->dp_ssect);
ssector = chs_ssect - 1 + dp->dp_shd * nsectors + chs_scyl * secpercyl
+ mbr_offset;
ssector1 = offset + dp->dp_start;
/*
* If ssector1 is on a cylinder >= 1024, then ssector can't be right.
* Allow the C/H/S for it to be 1023/ntracks-1/nsectors, or correct
* apart from the cylinder being reduced modulo 1024. Always allow
* 1023/255/63, because this is the official way to represent
* pure-LBA for the starting position.
*/
if ((ssector < ssector1
&& ((chs_ssect == nsectors && dp->dp_shd == ntracks - 1
&& chs_scyl == 1023)
|| (secpercyl != 0
&& (ssector1 - ssector) % (1024 * secpercyl) == 0)))
|| (dp->dp_scyl == 255 && dp->dp_shd == 255
&& dp->dp_ssect == 255)) {
TRACE(("%s: C/H/S start %d/%d/%d, start %lu: allow\n",
sname, chs_scyl, dp->dp_shd, chs_ssect, ssector1));
ssector = ssector1;
}
chs_ecyl = DPCYL(dp->dp_ecyl, dp->dp_esect);
chs_esect = DPSECT(dp->dp_esect);
esector = chs_esect - 1 + dp->dp_ehd * nsectors + chs_ecyl * secpercyl
+ mbr_offset;
esector1 = ssector1 + dp->dp_size - 1;
/*
* Allow certain bogus C/H/S values for esector, as above. However,
* heads == 255 isn't really legal and causes some BIOS crashes. The
* correct value to indicate a pure-LBA end is 1023/heads-1/sectors -
* usually 1023/254/63. "heads" is base 0, "sectors" is base 1.
*/
if ((esector < esector1
&& ((chs_esect == nsectors && dp->dp_ehd == ntracks - 1
&& chs_ecyl == 1023)
|| (secpercyl != 0
&& (esector1 - esector) % (1024 * secpercyl) == 0)))
|| (dp->dp_ecyl == 255 && dp->dp_ehd == 255
&& dp->dp_esect == 255)) {
TRACE(("%s: C/H/S end %d/%d/%d, end %lu: allow\n",
sname, chs_ecyl, dp->dp_ehd, chs_esect, esector1));
esector = esector1;
}
error = (ssector == ssector1 && esector == esector1) ? 0 : EINVAL;
if (bootverbose)
printf("%s: type 0x%x, start %lu, end = %lu, size %lu %s\n",
sname, dp->dp_typ, ssector1, esector1,
(u_long)dp->dp_size, error ? "" : ": OK");
if (ssector != ssector1 && bootverbose)
printf("%s: C/H/S start %d/%d/%d (%lu) != start %lu: invalid\n",
sname, chs_scyl, dp->dp_shd, chs_ssect,
ssector, ssector1);
if (esector != esector1 && bootverbose)
printf("%s: C/H/S end %d/%d/%d (%lu) != end %lu: invalid\n",
sname, chs_ecyl, dp->dp_ehd, chs_esect,
esector, esector1);
return (error);
}
int
dsinit(dev, lp, sspp)
dev_t dev;
struct disklabel *lp;
struct diskslices **sspp;
{
struct buf *bp;
u_char *cp;
int dospart;
struct dos_partition *dp;
struct dos_partition *dp0;
struct dos_partition dpcopy[NDOSPART];
int error;
int max_ncyls;
int max_nsectors;
int max_ntracks;
u_long mbr_offset;
char partname[2];
u_long secpercyl;
char *sname;
struct diskslice *sp;
struct diskslices *ssp;
mbr_offset = DOSBBSECTOR;
reread_mbr:
/* Read master boot record. */
bp = geteblk((int)lp->d_secsize);
bp->b_dev = dkmodpart(dkmodslice(dev, WHOLE_DISK_SLICE), RAW_PART);
bp->b_blkno = mbr_offset;
bp->b_bcount = lp->d_secsize;
bp->b_iocmd = BIO_READ;
DEV_STRATEGY(bp);
if (bufwait(bp) != 0) {
disk_err(&bp->b_io, "reading primary partition table: error",
0, 1);
error = EIO;
goto done;
}
/* Weakly verify it. */
cp = bp->b_data;
sname = dsname(dev, dkunit(dev), WHOLE_DISK_SLICE, RAW_PART, partname);
if (cp[0x1FE] != 0x55 || cp[0x1FF] != 0xAA) {
if (bootverbose)
printf("%s: invalid primary partition table: no magic\n",
sname);
error = EINVAL;
goto done;
}
/* Make a copy of the partition table to avoid alignment problems. */
memcpy(&dpcopy[0], cp + DOSPARTOFF, sizeof(dpcopy));
dp0 = &dpcopy[0];
/* Check for "Ontrack Diskmanager". */
for (dospart = 0, dp = dp0; dospart < NDOSPART; dospart++, dp++) {
if (dp->dp_typ == DOSPTYP_ONTRACK) {
if (bootverbose)
printf(
"%s: Found \"Ontrack Disk Manager\" on this disk.\n", sname);
bp->b_flags |= B_INVAL | B_AGE;
brelse(bp);
mbr_offset = 63;
goto reread_mbr;
}
}
if (bcmp(dp0, historical_bogus_partition_table,
sizeof historical_bogus_partition_table) == 0 ||
bcmp(dp0, historical_bogus_partition_table_fixed,
sizeof historical_bogus_partition_table_fixed) == 0) {
if (bootverbose)
printf(
"%s: invalid primary partition table: Dangerously Dedicated (ignored)\n",
sname);
error = EINVAL;
goto done;
}
/* Guess the geometry. */
/*
* TODO:
* Perhaps skip entries with 0 size.
* Perhaps only look at entries of type DOSPTYP_386BSD.
*/
max_ncyls = 0;
max_nsectors = 0;
max_ntracks = 0;
for (dospart = 0, dp = dp0; dospart < NDOSPART; dospart++, dp++) {
int ncyls;
int nsectors;
int ntracks;
ncyls = DPCYL(dp->dp_ecyl, dp->dp_esect) + 1;
if (max_ncyls < ncyls)
max_ncyls = ncyls;
nsectors = DPSECT(dp->dp_esect);
if (max_nsectors < nsectors)
max_nsectors = nsectors;
ntracks = dp->dp_ehd + 1;
if (max_ntracks < ntracks)
max_ntracks = ntracks;
}
/*
* Check that we have guessed the geometry right by checking the
* partition entries.
*/
/*
* TODO:
* As above.
* Check for overlaps.
* Check against d_secperunit if the latter is reliable.
*/
error = 0;
for (dospart = 0, dp = dp0; dospart < NDOSPART; dospart++, dp++) {
if (dp->dp_scyl == 0 && dp->dp_shd == 0 && dp->dp_ssect == 0
&& dp->dp_start == 0 && dp->dp_size == 0)
continue;
sname = dsname(dev, dkunit(dev), BASE_SLICE + dospart,
RAW_PART, partname);
/*
* Temporarily ignore errors from this check. We could
* simplify things by accepting the table eariler if we
* always ignore errors here. Perhaps we should always
* accept the table if the magic is right but not let
* bad entries affect the geometry.
*/
check_part(sname, dp, mbr_offset, max_nsectors, max_ntracks,
mbr_offset);
}
if (error != 0)
goto done;
/*
* Accept the DOS partition table.
* First adjust the label (we have been careful not to change it
* before we can guarantee success).
*/
secpercyl = (u_long)max_nsectors * max_ntracks;
if (secpercyl != 0) {
lp->d_nsectors = max_nsectors;
lp->d_ntracks = max_ntracks;
lp->d_secpercyl = secpercyl;
lp->d_ncylinders = lp->d_secperunit / secpercyl;
}
/*
* We are passed a pointer to a suitably initialized minimal
* slices "struct" with no dangling pointers in it. Replace it
* by a maximal one. This usually oversizes the "struct", but
* enlarging it while searching for logical drives would be
* inconvenient.
*/
free(*sspp, M_DEVBUF);
ssp = dsmakeslicestruct(MAX_SLICES, lp);
*sspp = ssp;
/* Initialize normal slices. */
sp = &ssp->dss_slices[BASE_SLICE];
for (dospart = 0, dp = dp0; dospart < NDOSPART; dospart++, dp++, sp++) {
sname = dsname(dev, dkunit(dev), BASE_SLICE + dospart,
RAW_PART, partname);
(void)mbr_setslice(sname, lp, sp, dp, mbr_offset);
}
ssp->dss_nslices = BASE_SLICE + NDOSPART;
/* Handle extended partitions. */
sp -= NDOSPART;
for (dospart = 0; dospart < NDOSPART; dospart++, sp++)
if (sp->ds_type == DOSPTYP_EXTENDED ||
sp->ds_type == DOSPTYP_EXTENDEDX)
mbr_extended(bp->b_dev, lp, ssp,
sp->ds_offset, sp->ds_size, sp->ds_offset,
max_nsectors, max_ntracks, mbr_offset, 1);
/*
* mbr_extended() abuses ssp->dss_nslices for the number of slices
* that would be found if there were no limit on the number of slices
* in *ssp. Cut it back now.
*/
if (ssp->dss_nslices > MAX_SLICES)
ssp->dss_nslices = MAX_SLICES;
done:
bp->b_flags |= B_INVAL | B_AGE;
brelse(bp);
if (error == EINVAL)
error = 0;
return (error);
}
static void
mbr_extended(dev, lp, ssp, ext_offset, ext_size, base_ext_offset, nsectors,
ntracks, mbr_offset, level)
dev_t dev;
struct disklabel *lp;
struct diskslices *ssp;
u_long ext_offset;
u_long ext_size;
u_long base_ext_offset;
int nsectors;
int ntracks;
u_long mbr_offset;
int level;
{
struct buf *bp;
u_char *cp;
int dospart;
struct dos_partition *dp;
struct dos_partition dpcopy[NDOSPART];
u_long ext_offsets[NDOSPART];
u_long ext_sizes[NDOSPART];
char partname[2];
int slice;
char *sname;
struct diskslice *sp;
if (level >= 16) {
printf(
"%s: excessive recursion in search for slices; aborting search\n",
devtoname(dev));
return;
}
/* Read extended boot record. */
bp = geteblk((int)lp->d_secsize);
bp->b_dev = dev;
bp->b_blkno = ext_offset;
bp->b_bcount = lp->d_secsize;
bp->b_iocmd = BIO_READ;
DEV_STRATEGY(bp);
if (bufwait(bp) != 0) {
disk_err(&bp->b_io, "reading extended partition table: error",
0, 1);
goto done;
}
/* Weakly verify it. */
cp = bp->b_data;
if (cp[0x1FE] != 0x55 || cp[0x1FF] != 0xAA) {
sname = dsname(dev, dkunit(dev), WHOLE_DISK_SLICE, RAW_PART,
partname);
if (bootverbose)
printf("%s: invalid extended partition table: no magic\n",
sname);
goto done;
}
/* Make a copy of the partition table to avoid alignment problems. */
memcpy(&dpcopy[0], cp + DOSPARTOFF, sizeof(dpcopy));
slice = ssp->dss_nslices;
for (dospart = 0, dp = &dpcopy[0]; dospart < NDOSPART;
dospart++, dp++) {
ext_sizes[dospart] = 0;
if (dp->dp_scyl == 0 && dp->dp_shd == 0 && dp->dp_ssect == 0
&& dp->dp_start == 0 && dp->dp_size == 0)
continue;
if (dp->dp_typ == DOSPTYP_EXTENDED ||
dp->dp_typ == DOSPTYP_EXTENDEDX) {
static char buf[32];
sname = dsname(dev, dkunit(dev), WHOLE_DISK_SLICE,
RAW_PART, partname);
snprintf(buf, sizeof(buf), "%s", sname);
if (strlen(buf) < sizeof buf - 11)
strcat(buf, "<extended>");
check_part(buf, dp, base_ext_offset, nsectors,
ntracks, mbr_offset);
ext_offsets[dospart] = base_ext_offset + dp->dp_start;
ext_sizes[dospart] = dp->dp_size;
} else {
sname = dsname(dev, dkunit(dev), slice, RAW_PART,
partname);
check_part(sname, dp, ext_offset, nsectors, ntracks,
mbr_offset);
if (slice >= MAX_SLICES) {
printf("%s: too many slices\n", sname);
slice++;
continue;
}
sp = &ssp->dss_slices[slice];
if (mbr_setslice(sname, lp, sp, dp, ext_offset) != 0)
continue;
slice++;
}
}
ssp->dss_nslices = slice;
/* If we found any more slices, recursively find all the subslices. */
for (dospart = 0; dospart < NDOSPART; dospart++)
if (ext_sizes[dospart] != 0)
mbr_extended(dev, lp, ssp, ext_offsets[dospart],
ext_sizes[dospart], base_ext_offset,
nsectors, ntracks, mbr_offset, ++level);
done:
bp->b_flags |= B_INVAL | B_AGE;
brelse(bp);
}
static int
mbr_setslice(sname, lp, sp, dp, br_offset)
char *sname;
struct disklabel *lp;
struct diskslice *sp;
struct dos_partition *dp;
u_long br_offset;
{
u_long offset;
u_long size;
offset = br_offset + dp->dp_start;
if (offset > lp->d_secperunit || offset < br_offset) {
printf(
"%s: slice starts beyond end of the disk: rejecting it\n",
sname);
return (1);
}
size = lp->d_secperunit - offset;
if (size >= dp->dp_size)
size = dp->dp_size;
else
printf(
"%s: slice extends beyond end of disk: truncating from %lu to %lu sectors\n",
sname, (u_long)dp->dp_size, size);
sp->ds_offset = offset;
sp->ds_size = size;
sp->ds_type = dp->dp_typ;
#ifdef PC98_ATCOMPAT
/* Fake FreeBSD(98). */
if (sp->ds_type == DOSPTYP_386BSD)
sp->ds_type = 0x94;
#endif
#if 0
lp->d_subtype |= (lp->d_subtype & 3) | dospart | DSTYPE_INDOSPART;
#endif
return (0);
}
#ifdef __alpha__
void
alpha_fix_srm_checksum(bp)
struct buf *bp;
{
u_int64_t *p;
u_int64_t sum;
int i;
p = (u_int64_t *) bp->b_data;
sum = 0;
for (i = 0; i < 63; i++)
sum += p[i];
p[63] = sum;
}
#endif