1 /* 2 * T10 Data Integrity Field CRC16 calculation 3 * 4 * Copyright (c) 2007 Oracle Corporation. All rights reserved. 5 * Written by Martin K. Petersen <martin.petersen@oracle.com> 6 * 7 * This source code is licensed under the GNU General Public License, 8 * Version 2. See the file COPYING for more details. 9 */ 10 11 #include <linux/types.h> 12 #include <linux/module.h> 13 #include <linux/crc-t10dif.h> 14 #include <linux/err.h> 15 #include <linux/init.h> 16 #include <crypto/hash.h> 17 18 static struct crypto_shash *crct10dif_tfm; 19 20 __u16 crc_t10dif(const unsigned char *buffer, size_t len) 21 { 22 struct { 23 struct shash_desc shash; 24 char ctx[2]; 25 } desc; 26 int err; 27 28 desc.shash.tfm = crct10dif_tfm; 29 desc.shash.flags = 0; 30 *(__u16 *)desc.ctx = 0; 31 32 err = crypto_shash_update(&desc.shash, buffer, len); 33 BUG_ON(err); 34 35 return *(__u16 *)desc.ctx; 36 } 37 EXPORT_SYMBOL(crc_t10dif); 38 39 static int __init crc_t10dif_mod_init(void) 40 { 41 crct10dif_tfm = crypto_alloc_shash("crct10dif", 0, 0); 42 return PTR_RET(crct10dif_tfm); 43 } 44 45 static void __exit crc_t10dif_mod_fini(void) 46 { 47 crypto_free_shash(crct10dif_tfm); 48 } 49 50 module_init(crc_t10dif_mod_init); 51 module_exit(crc_t10dif_mod_fini); 52 53 MODULE_DESCRIPTION("T10 DIF CRC calculation"); 54 MODULE_LICENSE("GPL"); 55