crypto/crct10dif_generic.c

   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 <[email protected]>
   8  * Copyright (C) 2013 Intel Corporation
   9  * Author: Tim Chen <[email protected]>
  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 a 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_update_arch(struct shash_desc *desc, const u8 *data,
  61                               unsigned int length)
  62 {
  63         struct chksum_desc_ctx *ctx = shash_desc_ctx(desc);
  64
  65         ctx->crc = crc_t10dif_update(ctx->crc, data, length);
  66         return 0;
  67 }
  68
  69 static int chksum_final(struct shash_desc *desc, u8 *out)
  70 {
  71         struct chksum_desc_ctx *ctx = shash_desc_ctx(desc);
  72
  73         *(__u16 *)out = ctx->crc;
  74         return 0;
  75 }
  76
  77 static int __chksum_finup(__u16 crc, const u8 *data, unsigned int len, u8 *out)
  78 {
  79         *(__u16 *)out = crc_t10dif_generic(crc, data, len);
  80         return 0;
  81 }
  82
  83 static int __chksum_finup_arch(__u16 crc, const u8 *data, unsigned int len,
  84                                u8 *out)
  85 {
  86         *(__u16 *)out = crc_t10dif_update(crc, data, len);
  87         return 0;
  88 }
  89
  90 static int chksum_finup(struct shash_desc *desc, const u8 *data,
  91                         unsigned int len, u8 *out)
  92 {
  93         struct chksum_desc_ctx *ctx = shash_desc_ctx(desc);
  94
  95         return __chksum_finup(ctx->crc, data, len, out);
  96 }
  97
  98 static int chksum_finup_arch(struct shash_desc *desc, const u8 *data,
  99                              unsigned int len, u8 *out)
 100 {
 101         struct chksum_desc_ctx *ctx = shash_desc_ctx(desc);
 102
 103         return __chksum_finup_arch(ctx->crc, data, len, out);
 104 }
 105
 106 static int chksum_digest(struct shash_desc *desc, const u8 *data,
 107                          unsigned int length, u8 *out)
 108 {
 109         return __chksum_finup(0, data, length, out);
 110 }
 111
 112 static int chksum_digest_arch(struct shash_desc *desc, const u8 *data,
 113                               unsigned int length, u8 *out)
 114 {
 115         return __chksum_finup_arch(0, data, length, out);
 116 }
 117
 118 static struct shash_alg algs[] = {{
 119         .digestsize             = CRC_T10DIF_DIGEST_SIZE,
 120         .init                   = chksum_init,
 121         .update                 = chksum_update,
 122         .final                  = chksum_final,
 123         .finup                  = chksum_finup,
 124         .digest                 = chksum_digest,
 125         .descsize               = sizeof(struct chksum_desc_ctx),
 126         .base.cra_name          = "crct10dif",
 127         .base.cra_driver_name   = "crct10dif-generic",
 128         .base.cra_priority      = 100,
 129         .base.cra_blocksize     = CRC_T10DIF_BLOCK_SIZE,
 130         .base.cra_module        = THIS_MODULE,
 131 }, {
 132         .digestsize             = CRC_T10DIF_DIGEST_SIZE,
 133         .init                   = chksum_init,
 134         .update                 = chksum_update_arch,
 135         .final                  = chksum_final,
 136         .finup                  = chksum_finup_arch,
 137         .digest                 = chksum_digest_arch,
 138         .descsize               = sizeof(struct chksum_desc_ctx),
 139         .base.cra_name          = "crct10dif",
 140         .base.cra_driver_name   = "crct10dif-" __stringify(ARCH),
 141         .base.cra_priority      = 150,
 142         .base.cra_blocksize     = CRC_T10DIF_BLOCK_SIZE,
 143         .base.cra_module        = THIS_MODULE,
 144 }};
 145
 146 static int num_algs;
 147
 148 static int __init crct10dif_mod_init(void)
 149 {
 150         /* register the arch flavor only if it differs from the generic one */
 151         num_algs = 1 + crc_t10dif_is_optimized();
 152
 153         return crypto_register_shashes(algs, num_algs);
 154 }
 155
 156 static void __exit crct10dif_mod_fini(void)
 157 {
 158         crypto_unregister_shashes(algs, num_algs);
 159 }
 160
 161 subsys_initcall(crct10dif_mod_init);
 162 module_exit(crct10dif_mod_fini);
 163
 164 MODULE_AUTHOR("Tim Chen <[email protected]>");
 165 MODULE_DESCRIPTION("T10 DIF CRC calculation.");
 166 MODULE_LICENSE("GPL");
 167 MODULE_ALIAS_CRYPTO("crct10dif");
 168 MODULE_ALIAS_CRYPTO("crct10dif-generic");