projects / linux-block.git / blame
| Commit | Line | Data |
|---|---|---|
| 78c37d19 AB |
1 | /* GPL HEADER START |
| 2 | * | |
| 3 | * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. | |
| 4 | * | |
| 5 | * This program is free software; you can redistribute it and/or modify | |
| 6 | * it under the terms of the GNU General Public License version 2 only, | |
| 7 | * as published by the Free Software Foundation. | |
| 8 | * | |
| 9 | * This program is distributed in the hope that it will be useful, but | |
| 10 | * WITHOUT ANY WARRANTY; without even the implied warranty of | |
| 11 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
| 12 | * General Public License version 2 for more details (a copy is included | |
| 13 | * in the LICENSE file that accompanied this code). | |
| 14 | * | |
| 15 | * You should have received a copy of the GNU General Public License | |
| 16 | * version 2 along with this program; If not, see http://www.gnu.org/licenses | |
| 17 | * | |
| 18 | * Please visit http://www.xyratex.com/contact if you need additional | |
| 19 | * information or have any questions. | |
| 20 | * | |
| 21 | * GPL HEADER END | |
| 22 | */ | |
| 23 | ||
| 24 | /* | |
| 25 | * Copyright 2012 Xyratex Technology Limited | |
| 26 | */ | |
| 27 | ||
| 28 | /* | |
| 29 | * This is crypto api shash wrappers to crc32_le. | |
| 30 | */ | |
| 31 | ||
| fffe7d92 | 32 | #include <asm/unaligned.h> |
| 78c37d19 AB |
33 | #include <linux/crc32.h> |
| 34 | #include <crypto/internal/hash.h> | |
| 35 | #include <linux/init.h> | |
| 36 | #include <linux/module.h> | |
| 37 | #include <linux/string.h> | |
| 38 | #include <linux/kernel.h> | |
| 39 | ||
| 40 | #define CHKSUM_BLOCK_SIZE 1 | |
| 41 | #define CHKSUM_DIGEST_SIZE 4 | |
| 42 | ||
| 43 | static u32 __crc32_le(u32 crc, unsigned char const *p, size_t len) | |
| 44 | { | |
| 45 | return crc32_le(crc, p, len); | |
| 46 | } | |
| 47 | ||
| 48 | /** No default init with ~0 */ | |
| 49 | static int crc32_cra_init(struct crypto_tfm *tfm) | |
| 50 | { | |
| 51 | u32 *key = crypto_tfm_ctx(tfm); | |
| 52 | ||
| 53 | *key = 0; | |
| 54 | ||
| 55 | return 0; | |
| 56 | } | |
| 57 | ||
| 58 | ||
| 59 | /* | |
| 60 | * Setting the seed allows arbitrary accumulators and flexible XOR policy | |
| 61 | * If your algorithm starts with ~0, then XOR with ~0 before you set | |
| 62 | * the seed. | |
| 63 | */ | |
| 64 | static int crc32_setkey(struct crypto_shash *hash, const u8 *key, | |
| 65 | unsigned int keylen) | |
| 66 | { | |
| 67 | u32 *mctx = crypto_shash_ctx(hash); | |
| 68 | ||
| 69 | if (keylen != sizeof(u32)) { | |
| 70 | crypto_shash_set_flags(hash, CRYPTO_TFM_RES_BAD_KEY_LEN); | |
| 71 | return -EINVAL; | |
| 72 | } | |
| fffe7d92 | 73 | *mctx = get_unaligned_le32(key); |
| 78c37d19 AB |
74 | return 0; |
| 75 | } | |
| 76 | ||
| 77 | static int crc32_init(struct shash_desc *desc) | |
| 78 | { | |
| 79 | u32 *mctx = crypto_shash_ctx(desc->tfm); | |
| 80 | u32 *crcp = shash_desc_ctx(desc); | |
| 81 | ||
| 82 | *crcp = *mctx; | |
| 83 | ||
| 84 | return 0; | |
| 85 | } | |
| 86 | ||
| 87 | static int crc32_update(struct shash_desc *desc, const u8 *data, | |
| 88 | unsigned int len) | |
| 89 | { | |
| 90 | u32 *crcp = shash_desc_ctx(desc); | |
| 91 | ||
| 92 | *crcp = __crc32_le(*crcp, data, len); | |
| 93 | return 0; | |
| 94 | } | |
| 95 | ||
| 96 | /* No final XOR 0xFFFFFFFF, like crc32_le */ | |
| 97 | static int __crc32_finup(u32 *crcp, const u8 *data, unsigned int len, | |
| 98 | u8 *out) | |
| 99 | { | |
| fffe7d92 | 100 | put_unaligned_le32(__crc32_le(*crcp, data, len), out); |
| 78c37d19 AB |
101 | return 0; |
| 102 | } | |
| 103 | ||
| 104 | static int crc32_finup(struct shash_desc *desc, const u8 *data, | |
| 105 | unsigned int len, u8 *out) | |
| 106 | { | |
| 107 | return __crc32_finup(shash_desc_ctx(desc), data, len, out); | |
| 108 | } | |
| 109 | ||
| 110 | static int crc32_final(struct shash_desc *desc, u8 *out) | |
| 111 | { | |
| 112 | u32 *crcp = shash_desc_ctx(desc); | |
| 113 | ||
| fffe7d92 | 114 | put_unaligned_le32(*crcp, out); |
| 78c37d19 AB |
115 | return 0; |
| 116 | } | |
| 117 | ||
| 118 | static int crc32_digest(struct shash_desc *desc, const u8 *data, | |
| 119 | unsigned int len, u8 *out) | |
| 120 | { | |
| 121 | return __crc32_finup(crypto_shash_ctx(desc->tfm), data, len, | |
| 122 | out); | |
| 123 | } | |
| 124 | static struct shash_alg alg = { | |
| 125 | .setkey = crc32_setkey, | |
| 126 | .init = crc32_init, | |
| 127 | .update = crc32_update, | |
| 128 | .final = crc32_final, | |
| 129 | .finup = crc32_finup, | |
| 130 | .digest = crc32_digest, | |
| 131 | .descsize = sizeof(u32), | |
| 132 | .digestsize = CHKSUM_DIGEST_SIZE, | |
| 133 | .base = { | |
| 134 | .cra_name = "crc32", | |
| a7c58ac0 | 135 | .cra_driver_name = "crc32-generic", |
| 78c37d19 | 136 | .cra_priority = 100, |
| a208fa8f | 137 | .cra_flags = CRYPTO_ALG_OPTIONAL_KEY, |
| 78c37d19 AB |
138 | .cra_blocksize = CHKSUM_BLOCK_SIZE, |
| 139 | .cra_ctxsize = sizeof(u32), | |
| 140 | .cra_module = THIS_MODULE, | |
| 141 | .cra_init = crc32_cra_init, | |
| 142 | } | |
| 143 | }; | |
| 144 | ||
| 145 | static int __init crc32_mod_init(void) | |
| 146 | { | |
| 147 | return crypto_register_shash(&alg); | |
| 148 | } | |
| 149 | ||
| 150 | static void __exit crc32_mod_fini(void) | |
| 151 | { | |
| 152 | crypto_unregister_shash(&alg); | |
| 153 | } | |
| 154 | ||
| 155 | module_init(crc32_mod_init); | |
| 156 | module_exit(crc32_mod_fini); | |
| 157 | ||
| 158 | MODULE_AUTHOR("Alexander Boyko <alexander_boyko@xyratex.com>"); | |
| 159 | MODULE_DESCRIPTION("CRC32 calculations wrapper for lib/crc32"); | |
| 160 | MODULE_LICENSE("GPL"); | |
| 5d26a105 | 161 | MODULE_ALIAS_CRYPTO("crc32"); |
| a7c58ac0 | 162 | MODULE_ALIAS_CRYPTO("crc32-generic"); |