| 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 | |