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|
/* $OpenBSD: disksubr.c,v 1.46 2007/06/12 20:57:42 deraadt Exp $ */
/* $NetBSD: disksubr.c,v 1.21 1996/05/03 19:42:03 christos Exp $ */
/*
* Copyright (c) 1996 Theo de Raadt
* 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. 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.
*
* @(#)ufs_disksubr.c 7.16 (Berkeley) 5/4/91
*/
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/buf.h>
#include <sys/device.h>
#include <sys/disklabel.h>
#include <sys/syslog.h>
#include <sys/disk.h>
#include <sys/reboot.h>
#include <sys/conf.h>
#include <machine/biosvar.h>
/*
* Attempt to read a disk label from a device
* using the indicated strategy routine.
* The label must be partly set up before this:
* secpercyl, secsize and anything required for a block i/o read
* operation in the driver's strategy/start routines
* must be filled in before calling us.
*
* If dos partition table requested, attempt to load it and
* find disklabel inside a DOS partition. Return buffer
* for use in signalling errors if requested.
*
* We would like to check if each MBR has a valid DOSMBR_SIGNATURE, but
* we cannot because it doesn't always exist. So.. we assume the
* MBR is valid.
*
* Returns null on success and an error string on failure.
*/
bios_diskinfo_t *bios_getdiskinfo(dev_t dev);
char *
readdisklabel(dev_t dev, void (*strat)(struct buf *),
struct disklabel *lp, struct cpu_disklabel *osdep, int spoofonly)
{
struct dos_partition dp[NDOSPART], *dp2;
struct partition *pp;
struct disklabel *dlp;
bios_diskinfo_t *pdi;
unsigned long extoff = 0;
unsigned int fattest;
struct buf *bp = NULL;
daddr64_t part_blkno = DOSBBSECTOR;
dev_t devno;
char *msg = NULL;
int dospartoff, cyl, i, ourpart = -1;
int wander = 1, n = 0, loop = 0;
/* minimal requirements for archetypal disk label */
if (lp->d_secsize < DEV_BSIZE)
lp->d_secsize = DEV_BSIZE;
if (DL_GETDSIZE(lp) == 0)
DL_SETDSIZE(lp, MAXDISKSIZE);
if (lp->d_secpercyl == 0) {
msg = "invalid geometry";
goto done;
}
lp->d_npartitions = RAW_PART + 1;
for (i = 0; i < RAW_PART; i++) {
DL_SETPSIZE(&lp->d_partitions[i], 0);
DL_SETPOFFSET(&lp->d_partitions[i], 0);
}
if (DL_GETPSIZE(&lp->d_partitions[i]) == 0)
DL_SETPSIZE(&lp->d_partitions[i], DL_GETDSIZE(lp));
DL_SETPOFFSET(&lp->d_partitions[i], 0);
/* Look for any BIOS geometry information we should honour. */
devno = chrtoblk(dev);
if (devno == NODEV)
devno = dev;
pdi = bios_getdiskinfo(MAKEBOOTDEV(major(devno), 0, 0, DISKUNIT(devno),
RAW_PART));
if (pdi != NULL && pdi->bios_heads > 0 && pdi->bios_sectors > 0) {
#ifdef DEBUG
printf("Disk GEOM %u/%u/%u -> BIOS GEOM %u/%u/%u\n",
lp->d_ntracks, lp->d_nsectors, lp->d_ncylinders,
pdi->bios_heads, pdi->bios_sectors,
DL_GETDSIZE(lp) / (pdi->bios_heads * pdi->bios_sectors));
#endif
lp->d_ntracks = pdi->bios_heads;
lp->d_nsectors = pdi->bios_sectors;
lp->d_secpercyl = pdi->bios_sectors * pdi->bios_heads;
lp->d_ncylinders = DL_GETDSIZE(lp) / lp->d_secpercyl;
}
/* get a buffer and initialize it */
bp = geteblk((int)lp->d_secsize);
bp->b_dev = dev;
/* do dos partitions in the process of getting disklabel? */
dospartoff = 0;
cyl = LABELSECTOR / lp->d_secpercyl;
/*
* Read dos partition table, follow extended partitions.
* Map the partitions to disklabel entries i-p
*/
while (wander && n < 8 && loop < 8) {
loop++;
wander = 0;
if (part_blkno < extoff)
part_blkno = extoff;
/* read boot record */
bp->b_blkno = part_blkno;
bp->b_bcount = lp->d_secsize;
bp->b_flags = B_BUSY | B_READ;
bp->b_cylinder = part_blkno / lp->d_secpercyl;
(*strat)(bp);
/* if successful, wander through dos partition table */
if (biowait(bp)) {
msg = "dos partition I/O error";
goto done;
}
bcopy(bp->b_data + DOSPARTOFF, dp, sizeof(dp));
if (ourpart == -1 && part_blkno == DOSBBSECTOR) {
/* Search for our MBR partition */
for (dp2=dp, i=0; i < NDOSPART && ourpart == -1;
i++, dp2++)
if (letoh32(dp2->dp_size) &&
dp2->dp_typ == DOSPTYP_OPENBSD)
ourpart = i;
if (ourpart == -1)
goto donot;
/*
* This is our MBR partition. need sector address
* for SCSI/IDE, cylinder for ESDI/ST506/RLL
*/
dp2 = &dp[ourpart];
dospartoff = letoh32(dp2->dp_start) + part_blkno;
cyl = DPCYL(dp2->dp_scyl, dp2->dp_ssect);
/* XXX build a temporary disklabel */
DL_SETPSIZE(&lp->d_partitions[0], letoh32(dp2->dp_size));
DL_SETPOFFSET(&lp->d_partitions[0],
letoh32(dp2->dp_start) + part_blkno);
if (lp->d_ntracks == 0)
lp->d_ntracks = dp2->dp_ehd + 1;
if (lp->d_nsectors == 0)
lp->d_nsectors = DPSECT(dp2->dp_esect);
if (lp->d_secpercyl == 0)
lp->d_secpercyl = lp->d_ntracks *
lp->d_nsectors;
}
donot:
/*
* In case the disklabel read below fails, we want to
* provide a fake label in i-p.
*/
for (dp2=dp, i=0; i < NDOSPART && n < 8; i++, dp2++) {
pp = &lp->d_partitions[8+n];
if (dp2->dp_typ == DOSPTYP_OPENBSD)
continue;
if (letoh32(dp2->dp_size) > DL_GETDSIZE(lp))
continue;
if (letoh32(dp2->dp_start) > DL_GETDSIZE(lp))
continue;
if (letoh32(dp2->dp_size) == 0)
continue;
if (letoh32(dp2->dp_start))
DL_SETPOFFSET(pp,
letoh32(dp2->dp_start) + part_blkno);
DL_SETPSIZE(pp, letoh32(dp2->dp_size));
switch (dp2->dp_typ) {
case DOSPTYP_UNUSED:
pp->p_fstype = FS_UNUSED;
n++;
break;
case DOSPTYP_LINUX:
pp->p_fstype = FS_EXT2FS;
n++;
break;
case DOSPTYP_FAT12:
case DOSPTYP_FAT16S:
case DOSPTYP_FAT16B:
case DOSPTYP_FAT16L:
case DOSPTYP_FAT32:
case DOSPTYP_FAT32L:
pp->p_fstype = FS_MSDOS;
n++;
break;
case DOSPTYP_EXTEND:
case DOSPTYP_EXTENDL:
part_blkno = letoh32(dp2->dp_start) + extoff;
if (!extoff) {
extoff = letoh32(dp2->dp_start);
part_blkno = 0;
}
wander = 1;
break;
default:
pp->p_fstype = FS_OTHER;
n++;
break;
}
}
}
lp->d_bbsize = 8192;
lp->d_sbsize = 64*1024; /* XXX ? */
lp->d_npartitions = MAXPARTITIONS;
if (n == 0 && part_blkno == DOSBBSECTOR) {
/* Check for a short jump instruction. */
fattest = ((bp->b_data[0] << 8) & 0xff00) | (bp->b_data[2] &
0xff);
if (fattest != 0xeb90 && fattest != 0xe900)
goto notfat;
/* Check for a valid bytes per sector value. */
fattest = ((bp->b_data[12] << 8) & 0xff00) | (bp->b_data[11] &
0xff);
if (fattest < 512 || fattest > 4096 || (fattest % 512 != 0))
goto notfat;
/* Check the end of sector marker. */
fattest = ((bp->b_data[510] << 8) & 0xff00) | (bp->b_data[511] &
0xff);
if (fattest != 0x55aa)
goto notfat;
/* Looks like a FAT filesystem. Spoof 'i'. */
DL_SETPSIZE(&lp->d_partitions['i' - 'a'],
DL_GETPSIZE(&lp->d_partitions[RAW_PART]));
DL_SETPOFFSET(&lp->d_partitions['i' - 'a'], 0);
lp->d_partitions['i' - 'a'].p_fstype = FS_MSDOS;
}
notfat:
/* don't read the on-disk label if we are in spoofed-only mode */
if (spoofonly)
goto done;
/* next, dig out disk label */
bp->b_blkno = dospartoff + LABELSECTOR;
bp->b_cylinder = cyl;
bp->b_bcount = lp->d_secsize;
bp->b_flags = B_BUSY | B_READ;
(*strat)(bp);
/* if successful, locate disk label within block and validate */
if (biowait(bp)) {
/* XXX we return the faked label built so far */
msg = "disk label I/O error";
goto done;
}
for (dlp = (struct disklabel *)bp->b_data;
dlp <= (struct disklabel *)(bp->b_data + lp->d_secsize - sizeof(*dlp));
dlp = (struct disklabel *)((char *)dlp + sizeof(long))) {
if (dlp->d_magic != DISKMAGIC || dlp->d_magic2 != DISKMAGIC) {
if (msg == NULL)
msg = "no disk label";
} else if (dlp->d_npartitions > MAXPARTITIONS ||
dkcksum(dlp) != 0)
msg = "disk label corrupted";
else {
DL_SETDSIZE(dlp, DL_GETDSIZE(lp));
*lp = *dlp;
msg = NULL;
break;
}
}
#if defined(CD9660)
if (msg && iso_disklabelspoof(dev, strat, lp) == 0)
msg = NULL;
#endif
#if defined(UDF)
if (msg && udf_disklabelspoof(dev, strat, lp) == 0)
msg = NULL;
#endif
done:
if (bp) {
bp->b_flags |= B_INVAL;
brelse(bp);
}
disklabeltokernlabel(lp);
return (msg);
}
/*
* Write disk label back to device after modification.
* XXX cannot handle OpenBSD partitions in extended partitions!
*/
int
writedisklabel(dev_t dev, void (*strat)(struct buf *),
struct disklabel *lp, struct cpu_disklabel *osdep)
{
struct dos_partition dp[NDOSPART], *dp2;
struct disklabel *dlp;
struct buf *bp = NULL;
int error, dospartoff, cyl, i;
int ourpart = -1;
/* get a buffer and initialize it */
bp = geteblk((int)lp->d_secsize);
bp->b_dev = dev;
/* do dos partitions in the process of getting disklabel? */
dospartoff = 0;
cyl = LABELSECTOR / lp->d_secpercyl;
/* read master boot record */
bp->b_blkno = DOSBBSECTOR;
bp->b_bcount = lp->d_secsize;
bp->b_flags = B_BUSY | B_READ;
bp->b_cylinder = DOSBBSECTOR / lp->d_secpercyl;
(*strat)(bp);
if ((error = biowait(bp)) != 0)
goto done;
/* XXX how do we check veracity/bounds of this? */
bcopy(bp->b_data + DOSPARTOFF, dp, sizeof(dp));
for (dp2=dp, i=0; i < NDOSPART && ourpart == -1; i++, dp2++)
if (letoh32(dp2->dp_size) && dp2->dp_typ == DOSPTYP_OPENBSD)
ourpart = i;
if (ourpart != -1) {
dp2 = &dp[ourpart];
/*
* need sector address for SCSI/IDE,
* cylinder for ESDI/ST506/RLL
*/
dospartoff = letoh32(dp2->dp_start);
cyl = DPCYL(dp2->dp_scyl, dp2->dp_ssect);
}
/* next, dig out disk label */
bp->b_blkno = dospartoff + LABELSECTOR;
bp->b_cylinder = cyl;
bp->b_bcount = lp->d_secsize;
bp->b_flags = B_BUSY | B_READ;
(*strat)(bp);
/* if successful, locate disk label within block and validate */
if ((error = biowait(bp)) != 0)
goto done;
for (dlp = (struct disklabel *)bp->b_data;
dlp <= (struct disklabel *)(bp->b_data + lp->d_secsize - sizeof(*dlp));
dlp = (struct disklabel *)((char *)dlp + sizeof(long))) {
if (dlp->d_magic == DISKMAGIC && dlp->d_magic2 == DISKMAGIC &&
dkcksum(dlp) == 0) {
*dlp = *lp;
bp->b_flags = B_BUSY | B_WRITE;
(*strat)(bp);
error = biowait(bp);
goto done;
}
}
/* Write it in the regular place. */
*(struct disklabel *)bp->b_data = *lp;
bp->b_flags = B_BUSY | B_WRITE;
(*strat)(bp);
error = biowait(bp);
done:
if (bp) {
bp->b_flags |= B_INVAL;
brelse(bp);
}
return (error);
}
|