| | 1 | /* |
| | 2 | * CRC32C |
| | 3 | *@Article{castagnoli-crc, |
| | 4 | * author = { Guy Castagnoli and Stefan Braeuer and Martin Herrman}, |
| | 5 | * title = {{Optimization of Cyclic Redundancy-Check Codes with 24 |
| | 6 | * and 32 Parity Bits}}, |
| | 7 | * journal = IEEE Transactions on Communication, |
| | 8 | * year = {1993}, |
| | 9 | * volume = {41}, |
| | 10 | * number = {6}, |
| | 11 | * pages = {}, |
| | 12 | * month = {June}, |
| | 13 | *} |
| | 14 | * Used by the iSCSI driver, possibly others, and derived from the |
| | 15 | * the iscsi-crc.c module of the linux-iscsi driver at |
| | 16 | * http://linux-iscsi.sourceforge.net. |
| | 17 | * |
| | 18 | * Following the example of lib/crc32, this function is intended to be |
| | 19 | * flexible and useful for all users. Modules that currently have their |
| | 20 | * own crc32c, but hopefully may be able to use this one are: |
| | 21 | * net/sctp (please add all your doco to here if you change to |
| | 22 | * use this one!) |
| | 23 | * <endoflist> |
| | 24 | * |
| | 25 | * Copyright (c) 2004 Cisco Systems, Inc. |
| | 26 | * |
| | 27 | * This program is free software; you can redistribute it and/or modify it |
| | 28 | * under the terms of the GNU General Public License as published by the Free |
| | 29 | * Software Foundation; either version 2 of the License, or (at your option) |
| | 30 | * any later version. |
| | 31 | * |
| | 32 | */ |
| | 33 | |
| | 34 | #include <crypto/hash.h> |
| | 35 | #include <linux/err.h> |
| | 36 | #include <linux/init.h> |
| | 37 | #include <linux/kernel.h> |
| | 38 | #include <linux/module.h> |
| | 39 | #include <linux/crc32c.h> |
| | 40 | |
| | 41 | static struct crypto_shash *tfm; |
| | 42 | |
| | 43 | u32 crc32c(u32 crc, const void *address, unsigned int length) |
| | 44 | { |
| | 45 | SHASH_DESC_ON_STACK(shash, tfm); |
| | 46 | u32 *ctx = (u32 *)shash_desc_ctx(shash); |
| | 47 | int err; |
| | 48 | |
| | 49 | shash->tfm = tfm; |
| | 50 | shash->flags = 0; |
| | 51 | *ctx = crc; |
| | 52 | |
| | 53 | err = crypto_shash_update(shash, address, length); |
| | 54 | BUG_ON(err); |
| | 55 | |
| | 56 | return *ctx; |
| | 57 | } |
| | 58 | |
| | 59 | EXPORT_SYMBOL(crc32c); |
| | 60 | |
| | 61 | static int __init libcrc32c_mod_init(void) |
| | 62 | { |
| | 63 | tfm = crypto_alloc_shash("crc32c", 0, 0); |
| | 64 | return PTR_ERR_OR_ZERO(tfm); |
| | 65 | } |
| | 66 | |
| | 67 | static void __exit libcrc32c_mod_fini(void) |
| | 68 | { |
| | 69 | crypto_free_shash(tfm); |
| | 70 | } |
| | 71 | |
| | 72 | module_init(libcrc32c_mod_init); |
| | 73 | module_exit(libcrc32c_mod_fini); |
| | 74 | |
| | 75 | MODULE_AUTHOR("Clay Haapala <chaapala@cisco.com>"); |
| | 76 | MODULE_DESCRIPTION("CRC32c (Castagnoli) calculations"); |
| | 77 | MODULE_LICENSE("GPL"); |
| | 78 | MODULE_SOFTDEP("pre: crc32c"); |
projects / linux-2.6-block.git / blame_incremental