xref: /freebsd/sys/geom/geom_bsd_enc.c (revision 74bf4e164ba5851606a27d4feff27717452583e5)
1 /*-
2  * Copyright (c) 2002 Poul-Henning Kamp
3  * Copyright (c) 2002 Networks Associates Technology, Inc.
4  * All rights reserved.
5  *
6  * This software was developed for the FreeBSD Project by Poul-Henning Kamp
7  * and NAI Labs, the Security Research Division of Network Associates, Inc.
8  * under DARPA/SPAWAR contract N66001-01-C-8035 ("CBOSS"), as part of the
9  * DARPA CHATS research program.
10  *
11  * Redistribution and use in source and binary forms, with or without
12  * modification, are permitted provided that the following conditions
13  * are met:
14  * 1. Redistributions of source code must retain the above copyright
15  *    notice, this list of conditions and the following disclaimer.
16  * 2. Redistributions in binary form must reproduce the above copyright
17  *    notice, this list of conditions and the following disclaimer in the
18  *    documentation and/or other materials provided with the distribution.
19  * 3. The names of the authors may not be used to endorse or promote
20  *    products derived from this software without specific prior written
21  *    permission.
22  *
23  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
24  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
25  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
26  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
27  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
28  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
29  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
30  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
31  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
32  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
33  * SUCH DAMAGE.
34  *
35  * Functions to encode and decode struct disklabel and struct partition into
36  * a bytestream of little endianess and correct packing.
37  *
38  * NB!  This file must be usable both in kernel and userland.
39  */
40 
41 #include <sys/cdefs.h>
42 __FBSDID("$FreeBSD$");
43 
44 #include <sys/types.h>
45 #include <sys/endian.h>
46 #include <sys/disklabel.h>
47 #include <sys/errno.h>
48 #ifdef _KERNEL
49 #include <sys/systm.h>
50 #else
51 #include <string.h>
52 #endif
53 
54 void
55 bsd_partition_le_dec(u_char *ptr, struct partition *d)
56 {
57 	d->p_size = le32dec(ptr + 0);
58 	d->p_offset = le32dec(ptr + 4);
59 	d->p_fsize = le32dec(ptr + 8);
60 	d->p_fstype = ptr[12];
61 	d->p_frag = ptr[13];
62 	d->p_cpg = le16dec(ptr + 14);
63 }
64 
65 int
66 bsd_disklabel_le_dec(u_char *ptr, struct disklabel *d, int maxpart)
67 {
68 	int i;
69 	u_char *p, *pe;
70 	uint16_t sum;
71 
72 	d->d_magic = le32dec(ptr + 0);
73 	if (d->d_magic != DISKMAGIC)
74 		return(EINVAL);
75 
76 	d->d_magic2 = le32dec(ptr + 132);
77 	if (d->d_magic2 != DISKMAGIC) {
78 		return(EINVAL);
79 	}
80 
81 	d->d_npartitions = le16dec(ptr + 138);
82 	if (d->d_npartitions > maxpart) {
83 		return(EINVAL);
84 	}
85 
86 	pe = ptr + 148 + 16 * d->d_npartitions;
87 	sum = 0;
88 	for (p = ptr; p < pe; p += 2)
89 		sum ^= le16dec(p);
90 	if (sum != 0) {
91 		return(EINVAL);
92 	}
93 
94 	d->d_type = le16dec(ptr + 4);
95 	d->d_subtype = le16dec(ptr + 6);
96 	bcopy(ptr + 8, d->d_typename, 16);
97 	bcopy(ptr + 24, d->d_packname, 16);
98 	d->d_secsize = le32dec(ptr + 40);
99 	d->d_nsectors = le32dec(ptr + 44);
100 	d->d_ntracks = le32dec(ptr + 48);
101 	d->d_ncylinders = le32dec(ptr + 52);
102 	d->d_secpercyl = le32dec(ptr + 56);
103 	d->d_secperunit = le32dec(ptr + 60);
104 	d->d_sparespertrack = le16dec(ptr + 64);
105 	d->d_sparespercyl = le16dec(ptr + 66);
106 	d->d_acylinders = le32dec(ptr + 68);
107 	d->d_rpm = le16dec(ptr + 72);
108 	d->d_interleave = le16dec(ptr + 74);
109 	d->d_trackskew = le16dec(ptr + 76);
110 	d->d_cylskew = le16dec(ptr + 78);
111 	d->d_headswitch = le32dec(ptr + 80);
112 	d->d_trkseek = le32dec(ptr + 84);
113 	d->d_flags = le32dec(ptr + 88);
114 	d->d_drivedata[0] = le32dec(ptr + 92);
115 	d->d_drivedata[1] = le32dec(ptr + 96);
116 	d->d_drivedata[2] = le32dec(ptr + 100);
117 	d->d_drivedata[3] = le32dec(ptr + 104);
118 	d->d_drivedata[4] = le32dec(ptr + 108);
119 	d->d_spare[0] = le32dec(ptr + 112);
120 	d->d_spare[1] = le32dec(ptr + 116);
121 	d->d_spare[2] = le32dec(ptr + 120);
122 	d->d_spare[3] = le32dec(ptr + 124);
123 	d->d_spare[4] = le32dec(ptr + 128);
124 	d->d_checksum = le16dec(ptr + 136);
125 	d->d_npartitions = le16dec(ptr + 138);
126 	d->d_bbsize = le32dec(ptr + 140);
127 	d->d_sbsize = le32dec(ptr + 144);
128 	for (i = 0; i < MAXPARTITIONS; i++)
129 		bsd_partition_le_dec(ptr + 148 + 16 * i, &d->d_partitions[i]);
130 	return(0);
131 }
132 
133 void
134 bsd_partition_le_enc(u_char *ptr, struct partition *d)
135 {
136 	le32enc(ptr + 0, d->p_size);
137 	le32enc(ptr + 4, d->p_offset);
138 	le32enc(ptr + 8, d->p_fsize);
139 	ptr[12] = d->p_fstype;
140 	ptr[13] = d->p_frag;
141 	le16enc(ptr + 14, d->p_cpg);
142 }
143 
144 void
145 bsd_disklabel_le_enc(u_char *ptr, struct disklabel *d)
146 {
147 	int i;
148 	u_char *p, *pe;
149 	uint16_t sum;
150 
151 	le32enc(ptr + 0, d->d_magic);
152 	le16enc(ptr + 4, d->d_type);
153 	le16enc(ptr + 6, d->d_subtype);
154 	bcopy(d->d_typename, ptr + 8, 16);
155 	bcopy(d->d_packname, ptr + 24, 16);
156 	le32enc(ptr + 40, d->d_secsize);
157 	le32enc(ptr + 44, d->d_nsectors);
158 	le32enc(ptr + 48, d->d_ntracks);
159 	le32enc(ptr + 52, d->d_ncylinders);
160 	le32enc(ptr + 56, d->d_secpercyl);
161 	le32enc(ptr + 60, d->d_secperunit);
162 	le16enc(ptr + 64, d->d_sparespertrack);
163 	le16enc(ptr + 66, d->d_sparespercyl);
164 	le32enc(ptr + 68, d->d_acylinders);
165 	le16enc(ptr + 72, d->d_rpm);
166 	le16enc(ptr + 74, d->d_interleave);
167 	le16enc(ptr + 76, d->d_trackskew);
168 	le16enc(ptr + 78, d->d_cylskew);
169 	le32enc(ptr + 80, d->d_headswitch);
170 	le32enc(ptr + 84, d->d_trkseek);
171 	le32enc(ptr + 88, d->d_flags);
172 	le32enc(ptr + 92, d->d_drivedata[0]);
173 	le32enc(ptr + 96, d->d_drivedata[1]);
174 	le32enc(ptr + 100, d->d_drivedata[2]);
175 	le32enc(ptr + 104, d->d_drivedata[3]);
176 	le32enc(ptr + 108, d->d_drivedata[4]);
177 	le32enc(ptr + 112, d->d_spare[0]);
178 	le32enc(ptr + 116, d->d_spare[1]);
179 	le32enc(ptr + 120, d->d_spare[2]);
180 	le32enc(ptr + 124, d->d_spare[3]);
181 	le32enc(ptr + 128, d->d_spare[4]);
182 	le32enc(ptr + 132, d->d_magic2);
183 	le16enc(ptr + 136, 0);
184 	le16enc(ptr + 138, d->d_npartitions);
185 	le32enc(ptr + 140, d->d_bbsize);
186 	le32enc(ptr + 144, d->d_sbsize);
187 	for (i = 0; i < d->d_npartitions; i++)
188 		bsd_partition_le_enc(ptr + 148 + 16 * i, &d->d_partitions[i]);
189 	pe = ptr + 148 + 16 * d->d_npartitions;
190 	sum = 0;
191 	for (p = ptr; p < pe; p += 2)
192 		sum ^= le16dec(p);
193 	le16enc(ptr + 136, sum);
194 }
195