NetBSD/lib/libukfs/ukfs_disklabel.c
pooka 27ec9b9d1d Add support for a byteswapped disklabel so that I can mount
NetBSD/sparc anita images on my i386.
2011-02-22 15:42:15 +00:00

151 lines
4.8 KiB
C

/* $NetBSD: ukfs_disklabel.c,v 1.3 2011/02/22 15:42:15 pooka Exp $ */
/*
* Local copies of libutil disklabel routines. This uncouples libukfs
* from the NetBSD-only libutil. All identifiers are prefixed with
* ukfs or UKFS, otherwise the routines are the same.
*/
/*
* From:
* NetBSD: disklabel_scan.c,v 1.3 2009/01/18 12:13:03 lukem Exp
*/
/*-
* Copyright (c) 2002 The NetBSD Foundation, Inc.
* All rights reserved.
*
* This code is derived from software contributed to The NetBSD Foundation
* by Roland C. Dowdeswell.
*
* 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 NETBSD FOUNDATION, INC. 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 FOUNDATION 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/types.h>
#include <string.h>
#include <unistd.h>
#include "ukfs_int_disklabel.h"
#define SCAN_INCR 4
int
ukfs__disklabel_scan(struct ukfs__disklabel *lp, int *isswapped,
char *buf, size_t buflen)
{
size_t i;
int imswapped;
uint16_t npart;
/* scan for the correct magic numbers. */
for (i=0; i <= buflen - sizeof(*lp); i += SCAN_INCR) {
memcpy(lp, buf + i, sizeof(*lp));
if (lp->d_magic == UKFS_DISKMAGIC &&
lp->d_magic2 == UKFS_DISKMAGIC) {
imswapped = 0;
goto sanity;
}
if (lp->d_magic == bswap32(UKFS_DISKMAGIC) &&
lp->d_magic2 == bswap32(UKFS_DISKMAGIC)) {
imswapped = 1;
goto sanity;
}
}
return 1;
sanity:
if (imswapped)
npart = bswap16(lp->d_npartitions);
else
npart = lp->d_npartitions;
/* we've found something, let's sanity check it */
if (npart > UKFS_MAXPARTITIONS
|| ukfs__disklabel_dkcksum(lp, imswapped))
return 1;
*isswapped = imswapped;
return 0;
}
/*
* From:
* $NetBSD: disklabel_dkcksum.c,v 1.4 2005/05/15 21:01:34 thorpej Exp
*/
/*-
* Copyright (c) 1991, 1993
* The 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.
*/
uint16_t
ukfs__disklabel_dkcksum(struct ukfs__disklabel *lp, int imswapped)
{
uint16_t *start, *end;
uint16_t sum;
uint16_t npart;
if (imswapped)
npart = bswap16(lp->d_npartitions);
else
npart = lp->d_npartitions;
sum = 0;
start = (uint16_t *)(void *)lp;
end = (uint16_t *)(void *)&lp->d_partitions[npart];
while (start < end) {
if (imswapped)
sum ^= bswap16(*start);
else
sum ^= *start;
start++;
}
return (sum);
}