geom_sunlabel_enc.c revision 113813 
1/*-
2 * Copyright (c) 2003 Jake Burkholder
3 * Copyright (c) 2003 Poul-Henning Kamp
4 * All rights reserved.
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met:
9 * 1. Redistributions of source code must retain the above copyright
10 *    notice, this list of conditions and the following disclaimer.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 *    notice, this list of conditions and the following disclaimer in the
13 *    documentation and/or other materials provided with the distribution.
14 *
15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
16 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
17 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
18 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
19 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
20 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
21 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
22 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
23 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
24 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
25 * SUCH DAMAGE.
26 *
27 * $FreeBSD: head/sys/geom/geom_sunlabel_enc.c 113813 2003-04-21 18:41:12Z phk $
28 *
29 * Functions to encode or decode struct sun_disklabel into a bytestream
30 * of correct endianess and packing.
31 *
32 * NB!  This file must be usable both in kernel and userland.
33 *
34 */
35
36#include <sys/types.h>
37#include <sys/endian.h>
38#include <sys/errno.h>
39#include <sys/sun_disklabel.h>
40
41#define	SL_TEXT		0x0
42#define	SL_TEXT_SIZEOF	0x80
43#define	SL_RPM		0x1a4
44#define	SL_PCYLINDERS	0x1a6
45#define	SL_SPARESPERCYL	0x1a8
46#define	SL_INTERLEAVE	0x1ae
47#define	SL_NCYLINDERS	0x1b0
48#define	SL_ACYLINDERS	0x1b2
49#define	SL_NTRACKS	0x1b4
50#define	SL_NSECTORS	0x1b6
51#define	SL_PART		0x1bc
52#define	SL_MAGIC	0x1fc
53#define	SL_CKSUM	0x1fe
54
55#define	SL_LENGTH	0x200
56
57#define	SL_NPART	0x8
58
59#define	SDKP_CYLOFFSET	0
60#define	SDKP_NSECTORS	0x4
61#define	SDKP_SIZEOF	0x8
62
63/*
64 * Decode the relevant fields of a sun disk label, and return zero if the
65 * magic and checksum works out OK.
66 */
67int
68sunlabel_dec(void const *pp, struct sun_disklabel *sl)
69{
70	const uint8_t *p;
71	size_t i;
72	u_int u;
73
74	p = pp;
75	for (i = 0; i < sizeof(sl->sl_text); i++)
76		sl->sl_text[i] = p[SL_TEXT + i];
77	sl->sl_rpm = be16dec(p + SL_RPM);
78	sl->sl_pcylinders = be16dec(p + SL_PCYLINDERS);
79	sl->sl_sparespercyl = be16dec(p + SL_SPARESPERCYL);
80	sl->sl_interleave = be16dec(p + SL_INTERLEAVE);
81	sl->sl_ncylinders = be16dec(p + SL_NCYLINDERS);
82	sl->sl_acylinders = be16dec(p + SL_ACYLINDERS);
83	sl->sl_ntracks = be16dec(p + SL_NTRACKS);
84	sl->sl_nsectors = be16dec(p + SL_NSECTORS);
85	for (i = 0; i < SL_NPART; i++) {
86		sl->sl_part[i].sdkp_cyloffset = be32dec(p + SL_PART +
87		    (i * SDKP_SIZEOF) + SDKP_CYLOFFSET);
88		sl->sl_part[i].sdkp_nsectors = be32dec(p + SL_PART +
89		    (i * SDKP_SIZEOF) + SDKP_NSECTORS);
90	}
91	sl->sl_magic = be16dec(p + SL_MAGIC);
92	for (i = u = 0; i < SL_LENGTH; i += 2)
93		u ^= be16dec(p + i);
94	if (u == 0 && sl->sl_magic == SUN_DKMAGIC)
95		return (0);
96	else
97		return (EINVAL);
98}
99
100/*
101 * Encode the relevant fields into a sun disklabel, compute new checksum.
102 */
103void
104sunlabel_enc(void *pp, struct sun_disklabel *sl)
105{
106	uint8_t *p;
107	size_t i;
108	u_int u;
109
110	p = pp;
111	for (i = 0; i < SL_TEXT_SIZEOF; i++)
112		p[SL_TEXT + i] = sl->sl_text[i];
113	be16enc(p + SL_RPM, sl->sl_rpm);
114	be16enc(p + SL_PCYLINDERS, sl->sl_pcylinders);
115	be16enc(p + SL_SPARESPERCYL, sl->sl_sparespercyl);
116	be16enc(p + SL_INTERLEAVE, sl->sl_interleave);
117	be16enc(p + SL_NCYLINDERS, sl->sl_ncylinders);
118	be16enc(p + SL_ACYLINDERS, sl->sl_acylinders);
119	be16enc(p + SL_NTRACKS, sl->sl_ntracks);
120	be16enc(p + SL_NSECTORS, sl->sl_nsectors);
121	for (i = 0; i < SL_NPART; i++) {
122		be32enc(p + SL_PART + (i * SDKP_SIZEOF) + SDKP_CYLOFFSET,
123		    sl->sl_part[i].sdkp_cyloffset);
124		be32enc(p + SL_PART + (i * SDKP_SIZEOF) + SDKP_NSECTORS,
125		    sl->sl_part[i].sdkp_nsectors);
126	}
127	be16enc(p + SL_MAGIC, sl->sl_magic);
128	for (i = u = 0; i < SL_LENGTH; i += 2)
129		u ^= be16dec(p + i);
130	be16enc(p + SL_CKSUM, u);
131}
132