1 /*-
2 * Copyright (c) 2003 Poul-Henning Kamp
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
13 *
14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24 * SUCH DAMAGE.
25 */
26
27 /* Functions to encode or decode struct dos_partition into a bytestream
28 * of correct endianess and packing. These functions do no validation
29 * or sanity checking, they only pack/unpack the fields correctly.
30 *
31 * NB! This file must be usable both in kernel and userland.
32 */
33
34 #include <sys/types.h>
35 #include <sys/endian.h>
36
37 #include "diskmbr.h"
38
39 static __inline uint32_t __unused
le32dec(const void * buf)40 le32dec(const void *buf)
41 {
42 const uint8_t *p = (const uint8_t *)buf;
43
44 return ((p[3] << 24) | (p[2] << 16) | (p[1] << 8) | p[0]);
45 }
46
47 static __inline void
le32enc(void * pp,uint32_t u)48 le32enc(void *pp, uint32_t u)
49 {
50 unsigned char *p = (unsigned char *)pp;
51
52 p[0] = u & 0xff;
53 p[1] = (u >> 8) & 0xff;
54 p[2] = (u >> 16) & 0xff;
55 p[3] = (u >> 24) & 0xff;
56 }
57
58 void
dos_partition_dec(void const * pp,struct dos_partition * d)59 dos_partition_dec(void const *pp, struct dos_partition *d)
60 {
61 unsigned char const *p = pp;
62
63 d->dp_flag = p[0];
64 d->dp_shd = p[1];
65 d->dp_ssect = p[2];
66 d->dp_scyl = p[3];
67 d->dp_typ = p[4];
68 d->dp_ehd = p[5];
69 d->dp_esect = p[6];
70 d->dp_ecyl = p[7];
71 d->dp_start = le32dec(p + 8);
72 d->dp_size = le32dec(p + 12);
73 }
74
75 void
dos_partition_enc(void * pp,struct dos_partition * d)76 dos_partition_enc(void *pp, struct dos_partition *d)
77 {
78 unsigned char *p = pp;
79
80 p[0] = d->dp_flag;
81 p[1] = d->dp_shd;
82 p[2] = d->dp_ssect;
83 p[3] = d->dp_scyl;
84 p[4] = d->dp_typ;
85 p[5] = d->dp_ehd;
86 p[6] = d->dp_esect;
87 p[7] = d->dp_ecyl;
88 le32enc(p + 8, d->dp_start);
89 le32enc(p + 12, d->dp_size);
90 }
91