1 /* $NetBSD: disklabel_swap.c,v 1.1 2021/05/17 08:50:36 mrg Exp $ */
2
3 /*
4 * Copyright (c) 1982, 1986, 1988 Regents of the University of California.
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 * 3. Neither the name of the University nor the names of its contributors
16 * may be used to endorse or promote products derived from this software
17 * without specific prior written permission.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29 * SUCH DAMAGE.
30 *
31 * @(#)ufs_disksubr.c 7.16 (Berkeley) 5/4/91
32 */
33
34 #include <sys/cdefs.h>
35 __KERNEL_RCSID(0, "$NetBSD: disklabel_swap.c,v 1.1 2021/05/17 08:50:36 mrg Exp $");
36
37 #ifdef _KERNEL_OPT
38 #include "opt_disklabel.h"
39 #endif /* _KERNEL_OPT */
40
41 #if defined(DISKLABEL_EI) || defined(LIBSA_DISKLABEL_EI)
42
43 #include <sys/param.h>
44 #include <sys/systm.h>
45 #include <sys/disklabel.h>
46 #include <sys/conf.h>
47 #include <lib/libkern/libkern.h>
48
49 /*
50 * from sh3/disksubr.c and kern/subr_disk_mbr.c with modifications:
51 * - update d_checksum properly
52 * - replace memcpy(9) by memmove(9) as a precaution
53 * - avoid memmove(9) for libkern version, check if the labels
54 * are the same and skip copying in-place.
55 */
56 void
disklabel_swap(struct disklabel * nlp,struct disklabel * olp)57 disklabel_swap(struct disklabel *nlp, struct disklabel *olp)
58 {
59 int i;
60 uint16_t npartitions;
61
62 #define SWAP16(x) nlp->x = bswap16(olp->x)
63 #define SWAP32(x) nlp->x = bswap32(olp->x)
64
65 SWAP32(d_magic);
66 SWAP16(d_type);
67 SWAP16(d_subtype);
68 if (nlp != olp) {
69 /* Do not need to swap char strings. */
70 memcpy(nlp->d_typename, olp->d_typename,
71 sizeof(nlp->d_typename));
72
73 /*
74 * XXX What should we do for d_un (an union of char and
75 * pointers)?
76 */
77 memcpy(nlp->d_packname, olp->d_packname,
78 sizeof(nlp->d_packname));
79 }
80
81 SWAP32(d_secsize);
82 SWAP32(d_nsectors);
83 SWAP32(d_ntracks);
84 SWAP32(d_ncylinders);
85 SWAP32(d_secpercyl);
86 SWAP32(d_secperunit);
87
88 SWAP16(d_sparespertrack);
89 SWAP16(d_sparespercyl);
90
91 SWAP32(d_acylinders);
92
93 SWAP16(d_rpm);
94 SWAP16(d_interleave);
95 SWAP16(d_trackskew);
96 SWAP16(d_cylskew);
97 SWAP32(d_headswitch);
98 SWAP32(d_trkseek);
99 SWAP32(d_flags);
100 for (i = 0; i < NDDATA; i++)
101 SWAP32(d_drivedata[i]);
102 for (i = 0; i < NSPARE; i++)
103 SWAP32(d_spare[i]);
104 SWAP32(d_magic2);
105 /* d_checksum is updated later. */
106
107 SWAP16(d_npartitions);
108 SWAP32(d_bbsize);
109 SWAP32(d_sbsize);
110 for (i = 0; i < MAXPARTITIONS; i++) {
111 SWAP32(d_partitions[i].p_size);
112 SWAP32(d_partitions[i].p_offset);
113 SWAP32(d_partitions[i].p_fsize);
114 /* p_fstype and p_frag is uint8_t, so no need to swap. */
115 nlp->d_partitions[i].p_fstype = olp->d_partitions[i].p_fstype;
116 nlp->d_partitions[i].p_frag = olp->d_partitions[i].p_frag;
117 SWAP16(d_partitions[i].p_cpg);
118 }
119
120 #undef SWAP16
121 #undef SWAP32
122
123 /* Update checksum in the target endian. */
124 nlp->d_checksum = 0;
125 npartitions = nlp->d_magic == DISKMAGIC ?
126 nlp->d_npartitions : olp->d_npartitions;
127 /*
128 * npartitions can be larger than MAXPARTITIONS when the label was not
129 * validated by setdisklabel. If so, the label is intentionally(?)
130 * corrupted and checksum should be meaningless.
131 */
132 if (npartitions <= MAXPARTITIONS)
133 nlp->d_checksum = dkcksum_sized(nlp, npartitions);
134 }
135 #endif /* DISKLABEL_EI || LIBSA_DISKLABEL_EI */
136