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 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(crc: ctx->crc, buffer: data, len: 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, buffer: 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(crc: 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(crc: 0, data, len: 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: &alg); |
108 | } |
109 | |
110 | static void __exit crct10dif_mod_fini(void) |
111 | { |
112 | crypto_unregister_shash(alg: &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 | |