geom_bsd_enc.c

/*-
 * SPDX-License-Identifier: BSD-3-Clause
 *
 * 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.
 * 3. The names of the authors may not be used to endorse or promote
 *    products derived from this software without specific prior written
 *    permission.
 *
 * 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.
 */

/*
 * Functions to encode and decode struct disklabel and struct partition into
 * a bytestream of little endianness and correct packing.
 *
 * NB!  This file must be usable both in kernel and userland.
 */

#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");

#include <sys/types.h>
#include <sys/endian.h>
#include <sys/disklabel.h>
#include <sys/errno.h>
#ifdef _KERNEL
#include <sys/systm.h>
#else
#include <string.h>
#endif

void
bsd_partition_le_dec(u_char *ptr, struct partition *d)
{
	d->p_size = le32dec(ptr + 0);
	d->p_offset = le32dec(ptr + 4);
	d->p_fsize = le32dec(ptr + 8);
	d->p_fstype = ptr[12];
	d->p_frag = ptr[13];
	d->p_cpg = le16dec(ptr + 14);
}

int
bsd_disklabel_le_dec(u_char *ptr, struct disklabel *d, int maxpart)
{
	int i;
	u_char *p, *pe;
	uint16_t sum;

	d->d_magic = le32dec(ptr + 0);
	if (d->d_magic != DISKMAGIC)
		return(EINVAL);

	d->d_magic2 = le32dec(ptr + 132);
	if (d->d_magic2 != DISKMAGIC) {
		return(EINVAL);
	}

	d->d_npartitions = le16dec(ptr + 138);
	if (d->d_npartitions > maxpart) {
		return(EINVAL);
	}

	pe = ptr + 148 + 16 * d->d_npartitions;
	sum = 0;
	for (p = ptr; p < pe; p += 2)
		sum ^= le16dec(p);
	if (sum != 0) {
		return(EINVAL);
	}

	d->d_type = le16dec(ptr + 4);
	d->d_subtype = le16dec(ptr + 6);
	bcopy(ptr + 8, d->d_typename, 16);
	bcopy(ptr + 24, d->d_packname, 16);
	d->d_secsize = le32dec(ptr + 40);
	d->d_nsectors = le32dec(ptr + 44);
	d->d_ntracks = le32dec(ptr + 48);
	d->d_ncylinders = le32dec(ptr + 52);
	d->d_secpercyl = le32dec(ptr + 56);
	d->d_secperunit = le32dec(ptr + 60);
	d->d_sparespertrack = le16dec(ptr + 64);
	d->d_sparespercyl = le16dec(ptr + 66);
	d->d_acylinders = le32dec(ptr + 68);
	d->d_rpm = le16dec(ptr + 72);
	d->d_interleave = le16dec(ptr + 74);
	d->d_trackskew = le16dec(ptr + 76);
	d->d_cylskew = le16dec(ptr + 78);
	d->d_headswitch = le32dec(ptr + 80);
	d->d_trkseek = le32dec(ptr + 84);
	d->d_flags = le32dec(ptr + 88);
	d->d_drivedata[0] = le32dec(ptr + 92);
	d->d_drivedata[1] = le32dec(ptr + 96);
	d->d_drivedata[2] = le32dec(ptr + 100);
	d->d_drivedata[3] = le32dec(ptr + 104);
	d->d_drivedata[4] = le32dec(ptr + 108);
	d->d_spare[0] = le32dec(ptr + 112);
	d->d_spare[1] = le32dec(ptr + 116);
	d->d_spare[2] = le32dec(ptr + 120);
	d->d_spare[3] = le32dec(ptr + 124);
	d->d_spare[4] = le32dec(ptr + 128);
	d->d_checksum = le16dec(ptr + 136);
	d->d_npartitions = le16dec(ptr + 138);
	d->d_bbsize = le32dec(ptr + 140);
	d->d_sbsize = le32dec(ptr + 144);
	for (i = 0; i < d->d_npartitions; i++)
		bsd_partition_le_dec(ptr + 148 + 16 * i, &d->d_partitions[i]);
	return(0);
}

void
bsd_partition_le_enc(u_char *ptr, struct partition *d)
{
	le32enc(ptr + 0, d->p_size);
	le32enc(ptr + 4, d->p_offset);
	le32enc(ptr + 8, d->p_fsize);
	ptr[12] = d->p_fstype;
	ptr[13] = d->p_frag;
	le16enc(ptr + 14, d->p_cpg);
}

void
bsd_disklabel_le_enc(u_char *ptr, struct disklabel *d)
{
	int i;
	u_char *p, *pe;
	uint16_t sum;

	le32enc(ptr + 0, d->d_magic);
	le16enc(ptr + 4, d->d_type);
	le16enc(ptr + 6, d->d_subtype);
	bcopy(d->d_typename, ptr + 8, 16);
	bcopy(d->d_packname, ptr + 24, 16);
	le32enc(ptr + 40, d->d_secsize);
	le32enc(ptr + 44, d->d_nsectors);
	le32enc(ptr + 48, d->d_ntracks);
	le32enc(ptr + 52, d->d_ncylinders);
	le32enc(ptr + 56, d->d_secpercyl);
	le32enc(ptr + 60, d->d_secperunit);
	le16enc(ptr + 64, d->d_sparespertrack);
	le16enc(ptr + 66, d->d_sparespercyl);
	le32enc(ptr + 68, d->d_acylinders);
	le16enc(ptr + 72, d->d_rpm);
	le16enc(ptr + 74, d->d_interleave);
	le16enc(ptr + 76, d->d_trackskew);
	le16enc(ptr + 78, d->d_cylskew);
	le32enc(ptr + 80, d->d_headswitch);
	le32enc(ptr + 84, d->d_trkseek);
	le32enc(ptr + 88, d->d_flags);
	le32enc(ptr + 92, d->d_drivedata[0]);
	le32enc(ptr + 96, d->d_drivedata[1]);
	le32enc(ptr + 100, d->d_drivedata[2]);
	le32enc(ptr + 104, d->d_drivedata[3]);
	le32enc(ptr + 108, d->d_drivedata[4]);
	le32enc(ptr + 112, d->d_spare[0]);
	le32enc(ptr + 116, d->d_spare[1]);
	le32enc(ptr + 120, d->d_spare[2]);
	le32enc(ptr + 124, d->d_spare[3]);
	le32enc(ptr + 128, d->d_spare[4]);
	le32enc(ptr + 132, d->d_magic2);
	le16enc(ptr + 136, 0);
	le16enc(ptr + 138, d->d_npartitions);
	le32enc(ptr + 140, d->d_bbsize);
	le32enc(ptr + 144, d->d_sbsize);
	for (i = 0; i < d->d_npartitions; i++)
		bsd_partition_le_enc(ptr + 148 + 16 * i, &d->d_partitions[i]);
	pe = ptr + 148 + 16 * d->d_npartitions;
	sum = 0;
	for (p = ptr; p < pe; p += 2)
		sum ^= le16dec(p);
	le16enc(ptr + 136, sum);
}