1 | /* $NetBSD: lfs_cksum.c,v 1.30 2015/08/02 18:18:10 dholland Exp $ */ |
2 | |
3 | /*- |
4 | * Copyright (c) 1999, 2000, 2001, 2002 The NetBSD Foundation, Inc. |
5 | * All rights reserved. |
6 | * |
7 | * This code is derived from software contributed to The NetBSD Foundation |
8 | * by Konrad E. Schroder <perseant@hhhh.org>. |
9 | * |
10 | * Redistribution and use in source and binary forms, with or without |
11 | * modification, are permitted provided that the following conditions |
12 | * are met: |
13 | * 1. Redistributions of source code must retain the above copyright |
14 | * notice, this list of conditions and the following disclaimer. |
15 | * 2. Redistributions in binary form must reproduce the above copyright |
16 | * notice, this list of conditions and the following disclaimer in the |
17 | * documentation and/or other materials provided with the distribution. |
18 | * |
19 | * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS |
20 | * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED |
21 | * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR |
22 | * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS |
23 | * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR |
24 | * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF |
25 | * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS |
26 | * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN |
27 | * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) |
28 | * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE |
29 | * POSSIBILITY OF SUCH DAMAGE. |
30 | */ |
31 | /*- |
32 | * Copyright (c) 1991, 1993 |
33 | * The Regents of the University of California. All rights reserved. |
34 | * |
35 | * Redistribution and use in source and binary forms, with or without |
36 | * modification, are permitted provided that the following conditions |
37 | * are met: |
38 | * 1. Redistributions of source code must retain the above copyright |
39 | * notice, this list of conditions and the following disclaimer. |
40 | * 2. Redistributions in binary form must reproduce the above copyright |
41 | * notice, this list of conditions and the following disclaimer in the |
42 | * documentation and/or other materials provided with the distribution. |
43 | * 3. Neither the name of the University nor the names of its contributors |
44 | * may be used to endorse or promote products derived from this software |
45 | * without specific prior written permission. |
46 | * |
47 | * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND |
48 | * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE |
49 | * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE |
50 | * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE |
51 | * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL |
52 | * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS |
53 | * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) |
54 | * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT |
55 | * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY |
56 | * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF |
57 | * SUCH DAMAGE. |
58 | * |
59 | * @(#)lfs_cksum.c 8.2 (Berkeley) 10/9/94 |
60 | */ |
61 | |
62 | #include <sys/cdefs.h> |
63 | __KERNEL_RCSID(0, "$NetBSD: lfs_cksum.c,v 1.30 2015/08/02 18:18:10 dholland Exp $" ); |
64 | |
65 | #include <sys/param.h> |
66 | #ifdef _KERNEL |
67 | # include <sys/systm.h> |
68 | # include <sys/lock.h> |
69 | #else |
70 | # include <stddef.h> |
71 | #endif |
72 | #include <sys/mount.h> |
73 | #include <ufs/lfs/lfs.h> |
74 | #include <ufs/lfs/lfs_extern.h> |
75 | |
76 | /* |
77 | * Simple, general purpose, fast checksum. Data must be short-aligned. |
78 | * Returns a u_long in case we ever want to do something more rigorous. |
79 | * |
80 | * XXX |
81 | * Use the TCP/IP checksum instead. |
82 | */ |
83 | u_int32_t |
84 | lfs_cksum_part(void *str, size_t len, u_int32_t sum) |
85 | { |
86 | |
87 | len &= ~(sizeof(u_int16_t) - 1); |
88 | for (; len; len -= sizeof(u_int16_t)) { |
89 | sum ^= *(u_int16_t *)str; |
90 | str = (void *)((u_int16_t *)str + 1); |
91 | } |
92 | return (sum); |
93 | } |
94 | |
95 | u_int32_t |
96 | cksum(void *str, size_t len) |
97 | { |
98 | |
99 | return lfs_cksum_fold(lfs_cksum_part(str, len, 0)); |
100 | } |
101 | |
102 | u_int32_t |
103 | lfs_sb_cksum(struct lfs *fs) |
104 | { |
105 | void *ptr; |
106 | size_t size; |
107 | |
108 | if (fs->lfs_is64) { |
109 | ptr = &fs->lfs_dlfs_u.u_64; |
110 | size = (size_t)offsetof(struct dlfs64, dlfs_cksum); |
111 | } else { |
112 | ptr = &fs->lfs_dlfs_u.u_32; |
113 | size = (size_t)offsetof(struct dlfs64, dlfs_cksum); |
114 | } |
115 | |
116 | return cksum(ptr, size); |
117 | } |
118 | |