xref: /NextBSD/sys/geom/geom_sunlabel_enc.c (revision eb1a5f8de9f7ea602c373a710f531abbf81141c4)
1 /*-
2  * Copyright (c) 2003 Jake Burkholder
3  * Copyright (c) 2003 Poul-Henning Kamp
4  * Copyright (c) 2004,2005 Joerg Wunsch
5  * All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  *
16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
17  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
20  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26  * SUCH DAMAGE.
27  */
28 /* Functions to encode or decode struct sun_disklabel into a bytestream
29  * of correct endianess and packing.
30  *
31  * NB!  This file must be usable both in kernel and userland.
32  */
33 
34 #include <sys/cdefs.h>
35 __FBSDID("$FreeBSD$");
36 
37 #include <sys/types.h>
38 #include <sys/endian.h>
39 #include <sys/errno.h>
40 #include <sys/sun_disklabel.h>
41 #ifdef _KERNEL
42 #include <sys/systm.h>
43 #else
44 #include <string.h>
45 #endif
46 
47 #define	SL_TEXT		0x0
48 #define	SL_TEXT_SIZEOF	0x80
49 #define	SL_VTOC_VERS	0x80
50 #define	SL_VTOC_VOLNAME	0x84
51 #define	SL_VTOC_NPART	0x8c
52 #define	SL_VTOC_MAP	0x8e
53 #define	SL_VTOC_SANITY	0xbc
54 #define	SL_RPM		0x1a4
55 #define	SL_PCYLINDERS	0x1a6
56 #define	SL_SPARESPERCYL	0x1a8
57 #define	SL_INTERLEAVE	0x1ae
58 #define	SL_NCYLINDERS	0x1b0
59 #define	SL_ACYLINDERS	0x1b2
60 #define	SL_NTRACKS	0x1b4
61 #define	SL_NSECTORS	0x1b6
62 #define	SL_PART		0x1bc
63 #define	SL_MAGIC	0x1fc
64 #define	SL_CKSUM	0x1fe
65 
66 #define	SDKP_CYLOFFSET	0
67 #define	SDKP_NSECTORS	0x4
68 #define	SDKP_SIZEOF	0x8	/* size of a partition entry */
69 
70 #define	SVTOC_TAG	0
71 #define	SVTOC_FLAG	0x2
72 #define	SVTOC_SIZEOF	0x4	/* size of a VTOC tag/flag entry */
73 
74 /*
75  * Decode the relevant fields of a sun disk label, and return zero if the
76  * magic and checksum works out OK.
77  */
78 int
sunlabel_dec(void const * pp,struct sun_disklabel * sl)79 sunlabel_dec(void const *pp, struct sun_disklabel *sl)
80 {
81 	const uint8_t *p;
82 	size_t i;
83 	u_int u;
84 	uint32_t vtocsane;
85 	uint16_t npart;
86 
87 	p = pp;
88 	for (i = 0; i < sizeof(sl->sl_text); i++)
89 		sl->sl_text[i] = p[SL_TEXT + i];
90 	sl->sl_rpm = be16dec(p + SL_RPM);
91 	sl->sl_pcylinders = be16dec(p + SL_PCYLINDERS);
92 	sl->sl_sparespercyl = be16dec(p + SL_SPARESPERCYL);
93 	sl->sl_interleave = be16dec(p + SL_INTERLEAVE);
94 	sl->sl_ncylinders = be16dec(p + SL_NCYLINDERS);
95 	sl->sl_acylinders = be16dec(p + SL_ACYLINDERS);
96 	sl->sl_ntracks = be16dec(p + SL_NTRACKS);
97 	sl->sl_nsectors = be16dec(p + SL_NSECTORS);
98 	for (i = 0; i < SUN_NPART; i++) {
99 		sl->sl_part[i].sdkp_cyloffset = be32dec(p + SL_PART +
100 		    (i * SDKP_SIZEOF) + SDKP_CYLOFFSET);
101 		sl->sl_part[i].sdkp_nsectors = be32dec(p + SL_PART +
102 		    (i * SDKP_SIZEOF) + SDKP_NSECTORS);
103 	}
104 	sl->sl_magic = be16dec(p + SL_MAGIC);
105 	vtocsane = be32dec(p + SL_VTOC_SANITY);
106 	npart = be16dec(p + SL_VTOC_NPART);
107 	if (vtocsane == SUN_VTOC_SANE && npart == SUN_NPART) {
108 		/*
109 		 * Seems we've got SVR4-compatible VTOC information
110 		 * as well, decode it.
111 		 */
112 		sl->sl_vtoc_sane = vtocsane;
113 		sl->sl_vtoc_vers = be32dec(p + SL_VTOC_VERS);
114 		memcpy(sl->sl_vtoc_volname, p + SL_VTOC_VOLNAME,
115 		    SUN_VOLNAME_LEN);
116 		sl->sl_vtoc_nparts = SUN_NPART;
117 		for (i = 0; i < SUN_NPART; i++) {
118 			sl->sl_vtoc_map[i].svtoc_tag = be16dec(p +
119 				SL_VTOC_MAP + (i * SVTOC_SIZEOF) + SVTOC_TAG);
120 			sl->sl_vtoc_map[i].svtoc_flag = be16dec(p +
121 				SL_VTOC_MAP + (i * SVTOC_SIZEOF) + SVTOC_FLAG);
122 		}
123 	}
124 	for (i = u = 0; i < SUN_SIZE; i += 2)
125 		u ^= be16dec(p + i);
126 	if (u == 0 && sl->sl_magic == SUN_DKMAGIC)
127 		return (0);
128 	else
129 		return (EINVAL);
130 }
131 
132 /*
133  * Encode the relevant fields into a sun disklabel, compute new checksum.
134  */
135 void
sunlabel_enc(void * pp,struct sun_disklabel * sl)136 sunlabel_enc(void *pp, struct sun_disklabel *sl)
137 {
138 	uint8_t *p;
139 	size_t i;
140 	u_int u;
141 
142 	p = pp;
143 	for (i = 0; i < SL_TEXT_SIZEOF; i++)
144 		p[SL_TEXT + i] = sl->sl_text[i];
145 	be16enc(p + SL_RPM, sl->sl_rpm);
146 	be16enc(p + SL_PCYLINDERS, sl->sl_pcylinders);
147 	be16enc(p + SL_SPARESPERCYL, sl->sl_sparespercyl);
148 	be16enc(p + SL_INTERLEAVE, sl->sl_interleave);
149 	be16enc(p + SL_NCYLINDERS, sl->sl_ncylinders);
150 	be16enc(p + SL_ACYLINDERS, sl->sl_acylinders);
151 	be16enc(p + SL_NTRACKS, sl->sl_ntracks);
152 	be16enc(p + SL_NSECTORS, sl->sl_nsectors);
153 	for (i = 0; i < SUN_NPART; i++) {
154 		be32enc(p + SL_PART + (i * SDKP_SIZEOF) + SDKP_CYLOFFSET,
155 		    sl->sl_part[i].sdkp_cyloffset);
156 		be32enc(p + SL_PART + (i * SDKP_SIZEOF) + SDKP_NSECTORS,
157 		    sl->sl_part[i].sdkp_nsectors);
158 	}
159 	be16enc(p + SL_MAGIC, sl->sl_magic);
160 	if (sl->sl_vtoc_sane == SUN_VTOC_SANE
161 	    && sl->sl_vtoc_nparts == SUN_NPART) {
162 		/*
163 		 * Write SVR4-compatible VTOC elements.
164 		 */
165 		be32enc(p + SL_VTOC_VERS, sl->sl_vtoc_vers);
166 		be32enc(p + SL_VTOC_SANITY, SUN_VTOC_SANE);
167 		memcpy(p + SL_VTOC_VOLNAME, sl->sl_vtoc_volname,
168 		    SUN_VOLNAME_LEN);
169 		be16enc(p + SL_VTOC_NPART, SUN_NPART);
170 		for (i = 0; i < SUN_NPART; i++) {
171 			be16enc(p + SL_VTOC_MAP + (i * SVTOC_SIZEOF)
172 				+ SVTOC_TAG,
173 				sl->sl_vtoc_map[i].svtoc_tag);
174 			be16enc(p + SL_VTOC_MAP + (i * SVTOC_SIZEOF)
175 				+ SVTOC_FLAG,
176 				sl->sl_vtoc_map[i].svtoc_flag);
177 		}
178 	}
179 	for (i = u = 0; i < SUN_SIZE; i += 2)
180 		u ^= be16dec(p + i);
181 	be16enc(p + SL_CKSUM, u);
182 }
183