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/* $OpenBSD: mbr.c,v 1.36 2014/03/14 15:41:33 krw Exp $ */
/*
* Copyright (c) 1997 Tobias Weingartner
* 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/types.h>
#include <sys/fcntl.h>
#include <sys/ioctl.h>
#include <sys/stat.h>
#include <sys/param.h>
#include <sys/disklabel.h>
#include <sys/dkio.h>
#include <err.h>
#include <errno.h>
#include <util.h>
#include <stdio.h>
#include <unistd.h>
#include <stdlib.h>
#include <memory.h>
#include "disk.h"
#include "misc.h"
#include "mbr.h"
#include "part.h"
void
MBR_init(struct disk *disk, struct mbr *mbr)
{
daddr_t i;
u_int64_t adj;
/* Fix up given mbr for this disk */
mbr->part[0].flag = 0;
mbr->part[1].flag = 0;
mbr->part[2].flag = 0;
mbr->part[3].flag = DOSACTIVE;
mbr->signature = DOSMBR_SIGNATURE;
/* Use whole disk. Reserve first track, or first cyl, if possible. */
mbr->part[3].id = DOSPTYP_OPENBSD;
if (disk->real->heads > 1)
mbr->part[3].shead = 1;
else
mbr->part[3].shead = 0;
if (disk->real->heads < 2 && disk->real->cylinders > 1)
mbr->part[3].scyl = 1;
else
mbr->part[3].scyl = 0;
mbr->part[3].ssect = 1;
/* Go right to the end */
mbr->part[3].ecyl = disk->real->cylinders - 1;
mbr->part[3].ehead = disk->real->heads - 1;
mbr->part[3].esect = disk->real->sectors;
/* Fix up start/length fields */
PRT_fix_BN(disk, &mbr->part[3], 3);
#if defined(__powerpc__) || defined(__mips__)
/* Now fix up for the MS-DOS boot partition on PowerPC. */
mbr->part[0].flag = DOSACTIVE; /* Boot from dos part */
mbr->part[3].flag = 0;
mbr->part[3].ns += mbr->part[3].bs;
mbr->part[3].bs = mbr->part[0].bs + mbr->part[0].ns;
mbr->part[3].ns -= mbr->part[3].bs;
PRT_fix_CHS(disk, &mbr->part[3]);
if ((mbr->part[3].shead != 1) || (mbr->part[3].ssect != 1)) {
/* align the partition on a cylinder boundary */
mbr->part[3].shead = 0;
mbr->part[3].ssect = 1;
mbr->part[3].scyl += 1;
}
/* Fix up start/length fields */
PRT_fix_BN(disk, &mbr->part[3], 3);
#endif
/* Start OpenBSD MBR partition on a power of 2 block number. */
i = 1;
while (i < DL_SECTOBLK(&dl, mbr->part[3].bs))
i *= 2;
adj = DL_BLKTOSEC(&dl, i) - mbr->part[3].bs;
mbr->part[3].bs += adj;
mbr->part[3].ns -= adj;
PRT_fix_CHS(disk, &mbr->part[3]);
}
void
MBR_parse(struct disk *disk, struct dos_mbr *dos_mbr, off_t offset,
off_t reloff, struct mbr *mbr)
{
int i;
memcpy(mbr->code, dos_mbr->dmbr_boot, sizeof(mbr->code));
mbr->offset = offset;
mbr->reloffset = reloff;
mbr->signature = getshort(&dos_mbr->dmbr_sign);
for (i = 0; i < NDOSPART; i++)
PRT_parse(disk, &dos_mbr->dmbr_parts[i], offset, reloff,
&mbr->part[i]);
}
void
MBR_make(struct mbr *mbr, struct dos_mbr *dos_mbr)
{
int i;
memcpy(dos_mbr->dmbr_boot, mbr->code, sizeof(dos_mbr->dmbr_boot));
putshort(&dos_mbr->dmbr_sign, DOSMBR_SIGNATURE);
for (i = 0; i < NDOSPART; i++)
PRT_make(&mbr->part[i], mbr->offset, mbr->reloffset,
&dos_mbr->dmbr_parts[i]);
}
void
MBR_print(struct mbr *mbr, char *units)
{
int i;
/* Header */
printf("Signature: 0x%X\n",
(int)mbr->signature);
PRT_print(0, NULL, units);
/* Entries */
for (i = 0; i < NDOSPART; i++)
PRT_print(i, &mbr->part[i], units);
}
int
MBR_read(int fd, off_t where, struct dos_mbr *dos_mbr)
{
const int secsize = unit_types[SECTORS].conversion;
ssize_t len;
off_t off;
char *secbuf;
where *= secsize;
off = lseek(fd, where, SEEK_SET);
if (off != where)
return (-1);
secbuf = calloc(1, secsize);
if (secbuf == NULL)
return (-1);
len = read(fd, secbuf, secsize);
memcpy(dos_mbr, secbuf, sizeof(*dos_mbr));
free(secbuf);
if (len == -1)
return (-1);
if (len < sizeof(*dos_mbr)) {
/* short read */
errno = EIO;
return (-1);
}
return (0);
}
int
MBR_write(int fd, off_t where, struct dos_mbr *dos_mbr)
{
const int secsize = unit_types[SECTORS].conversion;
ssize_t len;
off_t off;
char *secbuf;
/* Read the sector we want to store the MBR in. */
where *= secsize;
off = lseek(fd, where, SEEK_SET);
if (off != where)
return (-1);
secbuf = calloc(1, secsize);
if (secbuf == NULL)
return (-1);
len = read(fd, secbuf, secsize);
if (len == -1 || len != secsize)
goto done;
/*
* Place the new MBR at the start of the sector and
* write the sector back to "disk".
*/
memcpy(secbuf, dos_mbr, sizeof(*dos_mbr));
off = lseek(fd, where, SEEK_SET);
if (off == where)
len = write(fd, secbuf, secsize);
else
len = -1;
done:
free(secbuf);
if (len == -1)
return (-1);
if (len != secsize) {
/* short read or write */
errno = EIO;
return (-1);
}
ioctl(fd, DIOCRLDINFO, 0);
return (0);
}
/*
* Parse the MBR partition table into 'mbr', leaving the rest of 'mbr'
* untouched.
*/
void
MBR_pcopy(struct disk *disk, struct mbr *mbr)
{
int i, fd, error;
struct dos_mbr dos_mbr;
fd = DISK_open(disk->name, O_RDONLY);
error = MBR_read(fd, 0, &dos_mbr);
close(fd);
if (error == -1)
return;
for (i = 0; i < NDOSPART; i++)
PRT_parse(disk, &dos_mbr.dmbr_parts[i], 0, 0, &mbr->part[i]);
}
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