1 /* 2 * Cryptographic API. 3 * 4 * T10 Data Integrity Field CRC16 Crypto Transform 5 * 6 * Copyright (c) 2007 Oracle Corporation. All rights reserved. 7 * Written by Martin K. Petersen <martin.petersen@oracle.com> 8 * Copyright (C) 2013 Intel Corporation 9 * Author: Tim Chen <tim.c.chen@linux.intel.com> 10 * 11 * This program is free software; you can redistribute it and/or modify it 12 * under the terms of the GNU General Public License as published by the Free 13 * 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 OF 18 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND 19 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS 20 * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN 21 * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN 22 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE 23 * 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 33 struct chksum_desc_ctx { 34 __u16 crc; 35 }; 36 37 /* 38 * Steps through buffer one byte at at time, calculates reflected 39 * crc using table. 40 */ 41 42 static 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 51 static 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 60 static 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 68 static 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 74 static 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 82 static 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 88 static 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 }; 104 105 static int __init crct10dif_mod_init(void) 106 { 107 return crypto_register_shash(&alg); 108 } 109 110 static void __exit crct10dif_mod_fini(void) 111 { 112 crypto_unregister_shash(&alg); 113 } 114 115 subsys_initcall(crct10dif_mod_init); 116 module_exit(crct10dif_mod_fini); 117 118 MODULE_AUTHOR("Tim Chen <tim.c.chen@linux.intel.com>"); 119 MODULE_DESCRIPTION("T10 DIF CRC calculation."); 120 MODULE_LICENSE("GPL"); 121 MODULE_ALIAS_CRYPTO("crct10dif"); 122 MODULE_ALIAS_CRYPTO("crct10dif-generic"); 123