Root/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 <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
33struct 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
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 *crcp, const u8 *data, unsigned int len,
69            u8 *out)
70{
71    *(__u16 *)out = crc_t10dif_generic(*crcp, data, len);
72    return 0;
73}
74
75static int chksum_finup(struct shash_desc *desc, const u8 *data,
76            unsigned int len, u8 *out)
77{
78    struct chksum_desc_ctx *ctx = shash_desc_ctx(desc);
79
80    return __chksum_finup(&ctx->crc, data, len, out);
81}
82
83static int chksum_digest(struct shash_desc *desc, const u8 *data,
84             unsigned int length, u8 *out)
85{
86    struct chksum_desc_ctx *ctx = shash_desc_ctx(desc);
87
88    return __chksum_finup(&ctx->crc, data, length, out);
89}
90
91static struct shash_alg alg = {
92    .digestsize = CRC_T10DIF_DIGEST_SIZE,
93    .init = chksum_init,
94    .update = chksum_update,
95    .final = chksum_final,
96    .finup = chksum_finup,
97    .digest = chksum_digest,
98    .descsize = sizeof(struct chksum_desc_ctx),
99    .base = {
100        .cra_name = "crct10dif",
101        .cra_driver_name = "crct10dif-generic",
102        .cra_priority = 100,
103        .cra_blocksize = CRC_T10DIF_BLOCK_SIZE,
104        .cra_module = THIS_MODULE,
105    }
106};
107
108static int __init crct10dif_mod_init(void)
109{
110    int ret;
111
112    ret = crypto_register_shash(&alg);
113    return ret;
114}
115
116static void __exit crct10dif_mod_fini(void)
117{
118    crypto_unregister_shash(&alg);
119}
120
121module_init(crct10dif_mod_init);
122module_exit(crct10dif_mod_fini);
123
124MODULE_AUTHOR("Tim Chen <tim.c.chen@linux.intel.com>");
125MODULE_DESCRIPTION("T10 DIF CRC calculation.");
126MODULE_LICENSE("GPL");
127MODULE_ALIAS("crct10dif");
128

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