[net-next-2.6.git] / crypto / crc32c.c

/*
 * Cryptographic API.
 *
 * CRC32C chksum
 *
 *@Article{castagnoli-crc,
 * author =       { Guy Castagnoli and Stefan Braeuer and Martin Herrman},
 * title =        {{Optimization of Cyclic Redundancy-Check Codes with 24
 *                 and 32 Parity Bits}},
 * journal =      IEEE Transactions on Communication,
 * year =         {1993},
 * volume =       {41},
 * number =       {6},
 * pages =        {},
 * month =        {June},
 *}
 * Used by the iSCSI driver, possibly others, and derived from the
 * the iscsi-crc.c module of the linux-iscsi driver at
 * http://linux-iscsi.sourceforge.net.
 *
 * Following the example of lib/crc32, this function is intended to be
 * flexible and useful for all users.  Modules that currently have their
 * own crc32c, but hopefully may be able to use this one are:
 *  net/sctp (please add all your doco to here if you change to
 *            use this one!)
 *  <endoflist>
 *
 * Copyright (c) 2004 Cisco Systems, Inc.
 * Copyright (c) 2008 Herbert Xu <herbert@gondor.apana.org.au>
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License as published by the Free
 * Software Foundation; either version 2 of the License, or (at your option)
 * any later version.
 *
 */

#include <crypto/internal/hash.h>
#include <linux/init.h>
#include <linux/module.h>
#include <linux/string.h>
#include <linux/kernel.h>

#define CHKSUM_BLOCK_SIZE	1
#define CHKSUM_DIGEST_SIZE	4

struct chksum_ctx {
	u32 key;
};

struct chksum_desc_ctx {
	u32 crc;
};

/*
 * This is the CRC-32C table
 * Generated with:
 * width = 32 bits
 * poly = 0x1EDC6F41
 * reflect input bytes = true
 * reflect output bytes = true
 */

static const u32 crc32c_table[256] = {
	0x00000000L, 0xF26B8303L, 0xE13B70F7L, 0x1350F3F4L,
	0xC79A971FL, 0x35F1141CL, 0x26A1E7E8L, 0xD4CA64EBL,
	0x8AD958CFL, 0x78B2DBCCL, 0x6BE22838L, 0x9989AB3BL,
	0x4D43CFD0L, 0xBF284CD3L, 0xAC78BF27L, 0x5E133C24L,
	0x105EC76FL, 0xE235446CL, 0xF165B798L, 0x030E349BL,
	0xD7C45070L, 0x25AFD373L, 0x36FF2087L, 0xC494A384L,
	0x9A879FA0L, 0x68EC1CA3L, 0x7BBCEF57L, 0x89D76C54L,
	0x5D1D08BFL, 0xAF768BBCL, 0xBC267848L, 0x4E4DFB4BL,
	0x20BD8EDEL, 0xD2D60DDDL, 0xC186FE29L, 0x33ED7D2AL,
	0xE72719C1L, 0x154C9AC2L, 0x061C6936L, 0xF477EA35L,
	0xAA64D611L, 0x580F5512L, 0x4B5FA6E6L, 0xB93425E5L,
	0x6DFE410EL, 0x9F95C20DL, 0x8CC531F9L, 0x7EAEB2FAL,
	0x30E349B1L, 0xC288CAB2L, 0xD1D83946L, 0x23B3BA45L,
	0xF779DEAEL, 0x05125DADL, 0x1642AE59L, 0xE4292D5AL,
	0xBA3A117EL, 0x4851927DL, 0x5B016189L, 0xA96AE28AL,
	0x7DA08661L, 0x8FCB0562L, 0x9C9BF696L, 0x6EF07595L,
	0x417B1DBCL, 0xB3109EBFL, 0xA0406D4BL, 0x522BEE48L,
	0x86E18AA3L, 0x748A09A0L, 0x67DAFA54L, 0x95B17957L,
	0xCBA24573L, 0x39C9C670L, 0x2A993584L, 0xD8F2B687L,
	0x0C38D26CL, 0xFE53516FL, 0xED03A29BL, 0x1F682198L,
	0x5125DAD3L, 0xA34E59D0L, 0xB01EAA24L, 0x42752927L,
	0x96BF4DCCL, 0x64D4CECFL, 0x77843D3BL, 0x85EFBE38L,
	0xDBFC821CL, 0x2997011FL, 0x3AC7F2EBL, 0xC8AC71E8L,
	0x1C661503L, 0xEE0D9600L, 0xFD5D65F4L, 0x0F36E6F7L,
	0x61C69362L, 0x93AD1061L, 0x80FDE395L, 0x72966096L,
	0xA65C047DL, 0x5437877EL, 0x4767748AL, 0xB50CF789L,
	0xEB1FCBADL, 0x197448AEL, 0x0A24BB5AL, 0xF84F3859L,
	0x2C855CB2L, 0xDEEEDFB1L, 0xCDBE2C45L, 0x3FD5AF46L,
	0x7198540DL, 0x83F3D70EL, 0x90A324FAL, 0x62C8A7F9L,
	0xB602C312L, 0x44694011L, 0x5739B3E5L, 0xA55230E6L,
	0xFB410CC2L, 0x092A8FC1L, 0x1A7A7C35L, 0xE811FF36L,
	0x3CDB9BDDL, 0xCEB018DEL, 0xDDE0EB2AL, 0x2F8B6829L,
	0x82F63B78L, 0x709DB87BL, 0x63CD4B8FL, 0x91A6C88CL,
	0x456CAC67L, 0xB7072F64L, 0xA457DC90L, 0x563C5F93L,
	0x082F63B7L, 0xFA44E0B4L, 0xE9141340L, 0x1B7F9043L,
	0xCFB5F4A8L, 0x3DDE77ABL, 0x2E8E845FL, 0xDCE5075CL,
	0x92A8FC17L, 0x60C37F14L, 0x73938CE0L, 0x81F80FE3L,
	0x55326B08L, 0xA759E80BL, 0xB4091BFFL, 0x466298FCL,
	0x1871A4D8L, 0xEA1A27DBL, 0xF94AD42FL, 0x0B21572CL,
	0xDFEB33C7L, 0x2D80B0C4L, 0x3ED04330L, 0xCCBBC033L,
	0xA24BB5A6L, 0x502036A5L, 0x4370C551L, 0xB11B4652L,
	0x65D122B9L, 0x97BAA1BAL, 0x84EA524EL, 0x7681D14DL,
	0x2892ED69L, 0xDAF96E6AL, 0xC9A99D9EL, 0x3BC21E9DL,
	0xEF087A76L, 0x1D63F975L, 0x0E330A81L, 0xFC588982L,
	0xB21572C9L, 0x407EF1CAL, 0x532E023EL, 0xA145813DL,
	0x758FE5D6L, 0x87E466D5L, 0x94B49521L, 0x66DF1622L,
	0x38CC2A06L, 0xCAA7A905L, 0xD9F75AF1L, 0x2B9CD9F2L,
	0xFF56BD19L, 0x0D3D3E1AL, 0x1E6DCDEEL, 0xEC064EEDL,
	0xC38D26C4L, 0x31E6A5C7L, 0x22B65633L, 0xD0DDD530L,
	0x0417B1DBL, 0xF67C32D8L, 0xE52CC12CL, 0x1747422FL,
	0x49547E0BL, 0xBB3FFD08L, 0xA86F0EFCL, 0x5A048DFFL,
	0x8ECEE914L, 0x7CA56A17L, 0x6FF599E3L, 0x9D9E1AE0L,
	0xD3D3E1ABL, 0x21B862A8L, 0x32E8915CL, 0xC083125FL,
	0x144976B4L, 0xE622F5B7L, 0xF5720643L, 0x07198540L,
	0x590AB964L, 0xAB613A67L, 0xB831C993L, 0x4A5A4A90L,
	0x9E902E7BL, 0x6CFBAD78L, 0x7FAB5E8CL, 0x8DC0DD8FL,
	0xE330A81AL, 0x115B2B19L, 0x020BD8EDL, 0xF0605BEEL,
	0x24AA3F05L, 0xD6C1BC06L, 0xC5914FF2L, 0x37FACCF1L,
	0x69E9F0D5L, 0x9B8273D6L, 0x88D28022L, 0x7AB90321L,
	0xAE7367CAL, 0x5C18E4C9L, 0x4F48173DL, 0xBD23943EL,
	0xF36E6F75L, 0x0105EC76L, 0x12551F82L, 0xE03E9C81L,
	0x34F4F86AL, 0xC69F7B69L, 0xD5CF889DL, 0x27A40B9EL,
	0x79B737BAL, 0x8BDCB4B9L, 0x988C474DL, 0x6AE7C44EL,
	0xBE2DA0A5L, 0x4C4623A6L, 0x5F16D052L, 0xAD7D5351L
};

/*
 * Steps through buffer one byte at at time, calculates reflected
 * crc using table.
 */

static u32 crc32c(u32 crc, const u8 *data, unsigned int length)
{
	while (length--)
		crc = crc32c_table[(crc ^ *data++) & 0xFFL] ^ (crc >> 8);

	return crc;
}

/*
 * Steps through buffer one byte at at time, calculates reflected
 * crc using table.
 */

static int chksum_init(struct shash_desc *desc)
{
	struct chksum_ctx *mctx = crypto_shash_ctx(desc->tfm);
	struct chksum_desc_ctx *ctx = shash_desc_ctx(desc);

	ctx->crc = mctx->key;

	return 0;
}

/*
 * Setting the seed allows arbitrary accumulators and flexible XOR policy
 * If your algorithm starts with ~0, then XOR with ~0 before you set
 * the seed.
 */
static int chksum_setkey(struct crypto_shash *tfm, const u8 *key,
			 unsigned int keylen)
{
	struct chksum_ctx *mctx = crypto_shash_ctx(tfm);

	if (keylen != sizeof(mctx->key)) {
		crypto_shash_set_flags(tfm, CRYPTO_TFM_RES_BAD_KEY_LEN);
		return -EINVAL;
	}
	mctx->key = le32_to_cpu(*(__le32 *)key);
	return 0;
}

static int chksum_update(struct shash_desc *desc, const u8 *data,
			 unsigned int length)
{
	struct chksum_desc_ctx *ctx = shash_desc_ctx(desc);

	ctx->crc = crc32c(ctx->crc, data, length);
	return 0;
}

static int chksum_final(struct shash_desc *desc, u8 *out)
{
	struct chksum_desc_ctx *ctx = shash_desc_ctx(desc);

	*(__le32 *)out = ~cpu_to_le32p(&ctx->crc);
	return 0;
}

static int __chksum_finup(u32 *crcp, const u8 *data, unsigned int len, u8 *out)
{
	*(__le32 *)out = ~cpu_to_le32(crc32c(*crcp, data, len));
	return 0;
}

static int chksum_finup(struct shash_desc *desc, const u8 *data,
			unsigned int len, u8 *out)
{
	struct chksum_desc_ctx *ctx = shash_desc_ctx(desc);

	return __chksum_finup(&ctx->crc, data, len, out);
}

static int chksum_digest(struct shash_desc *desc, const u8 *data,
			 unsigned int length, u8 *out)
{
	struct chksum_ctx *mctx = crypto_shash_ctx(desc->tfm);

	return __chksum_finup(&mctx->key, data, length, out);
}

static int crc32c_cra_init(struct crypto_tfm *tfm)
{
	struct chksum_ctx *mctx = crypto_tfm_ctx(tfm);

	mctx->key = ~0;
	return 0;
}

static struct shash_alg alg = {
	.digestsize		=	CHKSUM_DIGEST_SIZE,
	.setkey			=	chksum_setkey,
	.init   		= 	chksum_init,
	.update 		=	chksum_update,
	.final  		=	chksum_final,
	.finup  		=	chksum_finup,
	.digest  		=	chksum_digest,
	.descsize		=	sizeof(struct chksum_desc_ctx),
	.base			=	{
		.cra_name		=	"crc32c",
		.cra_driver_name	=	"crc32c-generic",
		.cra_priority		=	100,
		.cra_blocksize		=	CHKSUM_BLOCK_SIZE,
		.cra_alignmask		=	3,
		.cra_ctxsize		=	sizeof(struct chksum_ctx),
		.cra_module		=	THIS_MODULE,
		.cra_init		=	crc32c_cra_init,
	}
};

static int __init crc32c_mod_init(void)
{
	return crypto_register_shash(&alg);
}

static void __exit crc32c_mod_fini(void)
{
	crypto_unregister_shash(&alg);
}

module_init(crc32c_mod_init);
module_exit(crc32c_mod_fini);

MODULE_AUTHOR("Clay Haapala <chaapala@cisco.com>");
MODULE_DESCRIPTION("CRC32c (Castagnoli) calculations wrapper for lib/crc32c");
MODULE_LICENSE("GPL");
Commit	Line	Data
db83aabf	1	/*
1da177e4 LT	2	* Cryptographic API.
	3	*
	4	* CRC32C chksum
	5	*
69c35efc HX	6	*@Article{castagnoli-crc,
	7	* author = { Guy Castagnoli and Stefan Braeuer and Martin Herrman},
	8	* title = {{Optimization of Cyclic Redundancy-Check Codes with 24
	9	* and 32 Parity Bits}},
	10	* journal = IEEE Transactions on Communication,
	11	* year = {1993},
	12	* volume = {41},
	13	* number = {6},
	14	* pages = {},
	15	* month = {June},
	16	*}
	17	* Used by the iSCSI driver, possibly others, and derived from the
	18	* the iscsi-crc.c module of the linux-iscsi driver at
	19	* http://linux-iscsi.sourceforge.net.
1da177e4	20	*
69c35efc HX	21	* Following the example of lib/crc32, this function is intended to be
	22	* flexible and useful for all users. Modules that currently have their
	23	* own crc32c, but hopefully may be able to use this one are:
	24	* net/sctp (please add all your doco to here if you change to
	25	* use this one!)
	26	* <endoflist>
	27	*
	28	* Copyright (c) 2004 Cisco Systems, Inc.
5773a3e6 HX	29	* Copyright (c) 2008 Herbert Xu <herbert@gondor.apana.org.au>
5773a3e6 HX	30	*
1da177e4 LT	31	* This program is free software; you can redistribute it and/or modify it
1da177e4 LT	32	* under the terms of the GNU General Public License as published by the Free
db83aabf	33	* Software Foundation; either version 2 of the License, or (at your option)
1da177e4 LT	34	* any later version.
	35	*
	36	*/
5773a3e6 HX	37
5773a3e6 HX	38	#include <crypto/internal/hash.h>
1da177e4 LT	39	#include <linux/init.h>
	40	#include <linux/module.h>
	41	#include <linux/string.h>
25cdbcd9	42	#include <linux/kernel.h>
1da177e4	43
5773a3e6	44	#define CHKSUM_BLOCK_SIZE 1
1da177e4 LT	45	#define CHKSUM_DIGEST_SIZE 4
	46
	47	struct chksum_ctx {
25cdbcd9	48	u32 key;
1da177e4 LT	49	};
1da177e4 LT	50
faccc4bb HX	51	struct chksum_desc_ctx {
	52	u32 crc;
	53	};
	54
69c35efc HX	55	/*
	56	* This is the CRC-32C table
	57	* Generated with:
	58	* width = 32 bits
	59	* poly = 0x1EDC6F41
	60	* reflect input bytes = true
	61	* reflect output bytes = true
	62	*/
	63
	64	static const u32 crc32c_table[256] = {
	65	0x00000000L, 0xF26B8303L, 0xE13B70F7L, 0x1350F3F4L,
	66	0xC79A971FL, 0x35F1141CL, 0x26A1E7E8L, 0xD4CA64EBL,
	67	0x8AD958CFL, 0x78B2DBCCL, 0x6BE22838L, 0x9989AB3BL,
	68	0x4D43CFD0L, 0xBF284CD3L, 0xAC78BF27L, 0x5E133C24L,
	69	0x105EC76FL, 0xE235446CL, 0xF165B798L, 0x030E349BL,
	70	0xD7C45070L, 0x25AFD373L, 0x36FF2087L, 0xC494A384L,
	71	0x9A879FA0L, 0x68EC1CA3L, 0x7BBCEF57L, 0x89D76C54L,
	72	0x5D1D08BFL, 0xAF768BBCL, 0xBC267848L, 0x4E4DFB4BL,
	73	0x20BD8EDEL, 0xD2D60DDDL, 0xC186FE29L, 0x33ED7D2AL,
	74	0xE72719C1L, 0x154C9AC2L, 0x061C6936L, 0xF477EA35L,
	75	0xAA64D611L, 0x580F5512L, 0x4B5FA6E6L, 0xB93425E5L,
	76	0x6DFE410EL, 0x9F95C20DL, 0x8CC531F9L, 0x7EAEB2FAL,
	77	0x30E349B1L, 0xC288CAB2L, 0xD1D83946L, 0x23B3BA45L,
	78	0xF779DEAEL, 0x05125DADL, 0x1642AE59L, 0xE4292D5AL,
	79	0xBA3A117EL, 0x4851927DL, 0x5B016189L, 0xA96AE28AL,
	80	0x7DA08661L, 0x8FCB0562L, 0x9C9BF696L, 0x6EF07595L,
	81	0x417B1DBCL, 0xB3109EBFL, 0xA0406D4BL, 0x522BEE48L,
	82	0x86E18AA3L, 0x748A09A0L, 0x67DAFA54L, 0x95B17957L,
	83	0xCBA24573L, 0x39C9C670L, 0x2A993584L, 0xD8F2B687L,
	84	0x0C38D26CL, 0xFE53516FL, 0xED03A29BL, 0x1F682198L,
	85	0x5125DAD3L, 0xA34E59D0L, 0xB01EAA24L, 0x42752927L,
	86	0x96BF4DCCL, 0x64D4CECFL, 0x77843D3BL, 0x85EFBE38L,
	87	0xDBFC821CL, 0x2997011FL, 0x3AC7F2EBL, 0xC8AC71E8L,
	88	0x1C661503L, 0xEE0D9600L, 0xFD5D65F4L, 0x0F36E6F7L,
	89	0x61C69362L, 0x93AD1061L, 0x80FDE395L, 0x72966096L,
	90	0xA65C047DL, 0x5437877EL, 0x4767748AL, 0xB50CF789L,
	91	0xEB1FCBADL, 0x197448AEL, 0x0A24BB5AL, 0xF84F3859L,
	92	0x2C855CB2L, 0xDEEEDFB1L, 0xCDBE2C45L, 0x3FD5AF46L,
	93	0x7198540DL, 0x83F3D70EL, 0x90A324FAL, 0x62C8A7F9L,
	94	0xB602C312L, 0x44694011L, 0x5739B3E5L, 0xA55230E6L,
	95	0xFB410CC2L, 0x092A8FC1L, 0x1A7A7C35L, 0xE811FF36L,
	96	0x3CDB9BDDL, 0xCEB018DEL, 0xDDE0EB2AL, 0x2F8B6829L,
	97	0x82F63B78L, 0x709DB87BL, 0x63CD4B8FL, 0x91A6C88CL,
	98	0x456CAC67L, 0xB7072F64L, 0xA457DC90L, 0x563C5F93L,
	99	0x082F63B7L, 0xFA44E0B4L, 0xE9141340L, 0x1B7F9043L,
	100	0xCFB5F4A8L, 0x3DDE77ABL, 0x2E8E845FL, 0xDCE5075CL,
	101	0x92A8FC17L, 0x60C37F14L, 0x73938CE0L, 0x81F80FE3L,
	102	0x55326B08L, 0xA759E80BL, 0xB4091BFFL, 0x466298FCL,
	103	0x1871A4D8L, 0xEA1A27DBL, 0xF94AD42FL, 0x0B21572CL,
	104	0xDFEB33C7L, 0x2D80B0C4L, 0x3ED04330L, 0xCCBBC033L,
	105	0xA24BB5A6L, 0x502036A5L, 0x4370C551L, 0xB11B4652L,
	106	0x65D122B9L, 0x97BAA1BAL, 0x84EA524EL, 0x7681D14DL,
	107	0x2892ED69L, 0xDAF96E6AL, 0xC9A99D9EL, 0x3BC21E9DL,
	108	0xEF087A76L, 0x1D63F975L, 0x0E330A81L, 0xFC588982L,
	109	0xB21572C9L, 0x407EF1CAL, 0x532E023EL, 0xA145813DL,
	110	0x758FE5D6L, 0x87E466D5L, 0x94B49521L, 0x66DF1622L,
	111	0x38CC2A06L, 0xCAA7A905L, 0xD9F75AF1L, 0x2B9CD9F2L,
	112	0xFF56BD19L, 0x0D3D3E1AL, 0x1E6DCDEEL, 0xEC064EEDL,
	113	0xC38D26C4L, 0x31E6A5C7L, 0x22B65633L, 0xD0DDD530L,
	114	0x0417B1DBL, 0xF67C32D8L, 0xE52CC12CL, 0x1747422FL,
	115	0x49547E0BL, 0xBB3FFD08L, 0xA86F0EFCL, 0x5A048DFFL,
	116	0x8ECEE914L, 0x7CA56A17L, 0x6FF599E3L, 0x9D9E1AE0L,
	117	0xD3D3E1ABL, 0x21B862A8L, 0x32E8915CL, 0xC083125FL,
	118	0x144976B4L, 0xE622F5B7L, 0xF5720643L, 0x07198540L,
119	0x590AB964L, 0xAB613A67L, 0xB831C993L, 0x4A5A4A90L,
120	0x9E902E7BL, 0x6CFBAD78L, 0x7FAB5E8CL, 0x8DC0DD8FL,
121	0xE330A81AL, 0x115B2B19L, 0x020BD8EDL, 0xF0605BEEL,
122	0x24AA3F05L, 0xD6C1BC06L, 0xC5914FF2L, 0x37FACCF1L,
123	0x69E9F0D5L, 0x9B8273D6L, 0x88D28022L, 0x7AB90321L,
124	0xAE7367CAL, 0x5C18E4C9L, 0x4F48173DL, 0xBD23943EL,
125	0xF36E6F75L, 0x0105EC76L, 0x12551F82L, 0xE03E9C81L,
126	0x34F4F86AL, 0xC69F7B69L, 0xD5CF889DL, 0x27A40B9EL,
127	0x79B737BAL, 0x8BDCB4B9L, 0x988C474DL, 0x6AE7C44EL,
128	0xBE2DA0A5L, 0x4C4623A6L, 0x5F16D052L, 0xAD7D5351L
129	};
130
131	/*
132	* Steps through buffer one byte at at time, calculates reflected
133	* crc using table.
134	*/
135
136	static u32 crc32c(u32 crc, const u8 *data, unsigned int length)
137	{
138	while (length--)
139	crc = crc32c_table[(crc ^ *data++) & 0xFFL] ^ (crc >> 8);
140
141	return crc;
142	}
143
1da177e4	144	/*
db83aabf	145	* Steps through buffer one byte at at time, calculates reflected
1da177e4 LT	146	* crc using table.
	147	*/
	148
faccc4bb	149	static int chksum_init(struct shash_desc *desc)
1da177e4	150	{
faccc4bb HX	151	struct chksum_ctx *mctx = crypto_shash_ctx(desc->tfm);
	152	struct chksum_desc_ctx *ctx = shash_desc_ctx(desc);
	153
	154	ctx->crc = mctx->key;
1da177e4	155
faccc4bb	156	return 0;
1da177e4 LT	157	}
	158
	159	/*
	160	* Setting the seed allows arbitrary accumulators and flexible XOR policy
	161	* If your algorithm starts with ~0, then XOR with ~0 before you set
	162	* the seed.
	163	*/
faccc4bb	164	static int chksum_setkey(struct crypto_shash tfm, const u8 key,
560c06ae	165	unsigned int keylen)
1da177e4	166	{
faccc4bb	167	struct chksum_ctx *mctx = crypto_shash_ctx(tfm);
1da177e4	168
faccc4bb HX	169	if (keylen != sizeof(mctx->key)) {
faccc4bb HX	170	crypto_shash_set_flags(tfm, CRYPTO_TFM_RES_BAD_KEY_LEN);
1da177e4 LT	171	return -EINVAL;
1da177e4 LT	172	}
25cdbcd9	173	mctx->key = le32_to_cpu((__le32 )key);
1da177e4 LT	174	return 0;
	175	}
	176
faccc4bb HX	177	static int chksum_update(struct shash_desc desc, const u8 data,
faccc4bb HX	178	unsigned int length)
1da177e4	179	{
faccc4bb	180	struct chksum_desc_ctx *ctx = shash_desc_ctx(desc);
1da177e4	181
faccc4bb	182	ctx->crc = crc32c(ctx->crc, data, length);
25cdbcd9	183	return 0;
1da177e4 LT	184	}
1da177e4 LT	185
faccc4bb	186	static int chksum_final(struct shash_desc desc, u8 out)
5773a3e6	187	{
faccc4bb	188	struct chksum_desc_ctx *ctx = shash_desc_ctx(desc);
5773a3e6	189
faccc4bb	190	(__le32 )out = ~cpu_to_le32p(&ctx->crc);
5773a3e6 HX	191	return 0;
	192	}
	193
faccc4bb	194	static int __chksum_finup(u32 crcp, const u8 data, unsigned int len, u8 *out)
5773a3e6	195	{
faccc4bb	196	(__le32 )out = ~cpu_to_le32(crc32c(*crcp, data, len));
5773a3e6 HX	197	return 0;
	198	}
	199
faccc4bb HX	200	static int chksum_finup(struct shash_desc desc, const u8 data,
faccc4bb HX	201	unsigned int len, u8 *out)
5773a3e6	202	{
faccc4bb	203	struct chksum_desc_ctx *ctx = shash_desc_ctx(desc);
5773a3e6	204
faccc4bb	205	return __chksum_finup(&ctx->crc, data, len, out);
5773a3e6 HX	206	}
5773a3e6 HX	207
faccc4bb HX	208	static int chksum_digest(struct shash_desc desc, const u8 data,
faccc4bb HX	209	unsigned int length, u8 *out)
5773a3e6	210	{
faccc4bb	211	struct chksum_ctx *mctx = crypto_shash_ctx(desc->tfm);
5773a3e6	212
faccc4bb	213	return __chksum_finup(&mctx->key, data, length, out);
5773a3e6 HX	214	}
	215
	216	static int crc32c_cra_init(struct crypto_tfm *tfm)
	217	{
faccc4bb	218	struct chksum_ctx *mctx = crypto_tfm_ctx(tfm);
5773a3e6	219
faccc4bb	220	mctx->key = ~0;
5773a3e6 HX	221	return 0;
	222	}
	223
faccc4bb HX	224	static struct shash_alg alg = {
	225	.digestsize = CHKSUM_DIGEST_SIZE,
	226	.setkey = chksum_setkey,
	227	.init = chksum_init,
	228	.update = chksum_update,
	229	.final = chksum_final,
	230	.finup = chksum_finup,
	231	.digest = chksum_digest,
	232	.descsize = sizeof(struct chksum_desc_ctx),
	233	.base = {
	234	.cra_name = "crc32c",
	235	.cra_driver_name = "crc32c-generic",
	236	.cra_priority = 100,
	237	.cra_blocksize = CHKSUM_BLOCK_SIZE,
	238	.cra_alignmask = 3,
	239	.cra_ctxsize = sizeof(struct chksum_ctx),
	240	.cra_module = THIS_MODULE,
	241	.cra_init = crc32c_cra_init,
5773a3e6 HX	242	}
	243	};
	244
3af5b90b	245	static int __init crc32c_mod_init(void)
1da177e4	246	{
faccc4bb	247	return crypto_register_shash(&alg);
1da177e4 LT	248	}
1da177e4 LT	249
3af5b90b	250	static void __exit crc32c_mod_fini(void)
1da177e4	251	{
faccc4bb	252	crypto_unregister_shash(&alg);
1da177e4 LT	253	}
1da177e4 LT	254
3af5b90b KB	255	module_init(crc32c_mod_init);
3af5b90b KB	256	module_exit(crc32c_mod_fini);
1da177e4 LT	257
	258	MODULE_AUTHOR("Clay Haapala <chaapala@cisco.com>");
	259	MODULE_DESCRIPTION("CRC32c (Castagnoli) calculations wrapper for lib/crc32c");
	260	MODULE_LICENSE("GPL");