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1/*2 * Cryptographic API.3 *4 * T10 Data Integrity Field CRC16 Crypto Transform5 *6 * Copyright (c) 2007 Oracle Corporation. All rights reserved.7 * Written by Martin K. Petersen <martin.petersen@oracle.com>8 * Copyright (C) 2013 Intel Corporation9 * Author: Tim Chen <tim.c.chen@linux.intel.com>10 *11 * This program is free software; you can redistribute it and/or modify it12 * under the terms of the GNU General Public License as published by the Free13 * Software Foundation; either version 2 of the License, or (at your option)14 * any later version.15 *16 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,17 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF18 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND19 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS20 * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN21 * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN22 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE23 * SOFTWARE.24 *25 */26 27#include <linux/module.h>28#include <linux/crc-t10dif.h>29#include <crypto/internal/hash.h>30#include <linux/init.h>31#include <linux/kernel.h>32 33struct chksum_desc_ctx {34 __u16 crc;35};36 37/*38 * Steps through buffer one byte at a time, calculates reflected39 * crc using table.40 */41 42static int chksum_init(struct shash_desc *desc)43{44 struct chksum_desc_ctx *ctx = shash_desc_ctx(desc);45 46 ctx->crc = 0;47 48 return 0;49}50 51static int chksum_update(struct shash_desc *desc, const u8 *data,52 unsigned int length)53{54 struct chksum_desc_ctx *ctx = shash_desc_ctx(desc);55 56 ctx->crc = crc_t10dif_generic(ctx->crc, data, length);57 return 0;58}59 60static int chksum_final(struct shash_desc *desc, u8 *out)61{62 struct chksum_desc_ctx *ctx = shash_desc_ctx(desc);63 64 *(__u16 *)out = ctx->crc;65 return 0;66}67 68static int __chksum_finup(__u16 crc, const u8 *data, unsigned int len, u8 *out)69{70 *(__u16 *)out = crc_t10dif_generic(crc, data, len);71 return 0;72}73 74static int chksum_finup(struct shash_desc *desc, const u8 *data,75 unsigned int len, u8 *out)76{77 struct chksum_desc_ctx *ctx = shash_desc_ctx(desc);78 79 return __chksum_finup(ctx->crc, data, len, out);80}81 82static int chksum_digest(struct shash_desc *desc, const u8 *data,83 unsigned int length, u8 *out)84{85 return __chksum_finup(0, data, length, out);86}87 88static struct shash_alg alg = {89 .digestsize = CRC_T10DIF_DIGEST_SIZE,90 .init = chksum_init,91 .update = chksum_update,92 .final = chksum_final,93 .finup = chksum_finup,94 .digest = chksum_digest,95 .descsize = sizeof(struct chksum_desc_ctx),96 .base = {97 .cra_name = "crct10dif",98 .cra_driver_name = "crct10dif-generic",99 .cra_priority = 100,100 .cra_blocksize = CRC_T10DIF_BLOCK_SIZE,101 .cra_module = THIS_MODULE,102 }103};104 105static int __init crct10dif_mod_init(void)106{107 return crypto_register_shash(&alg);108}109 110static void __exit crct10dif_mod_fini(void)111{112 crypto_unregister_shash(&alg);113}114 115subsys_initcall(crct10dif_mod_init);116module_exit(crct10dif_mod_fini);117 118MODULE_AUTHOR("Tim Chen <tim.c.chen@linux.intel.com>");119MODULE_DESCRIPTION("T10 DIF CRC calculation.");120MODULE_LICENSE("GPL");121MODULE_ALIAS_CRYPTO("crct10dif");122MODULE_ALIAS_CRYPTO("crct10dif-generic");123