51 lines
		
	
	
	
		
			1.1 KiB
			
		
	
	
	
		
			C
		
	
	
	
	
	
		
		
			
		
	
	
			51 lines
		
	
	
	
		
			1.1 KiB
			
		
	
	
	
		
			C
		
	
	
	
	
	
|   | /*
 | ||
|  |  * Copyright (C) 2014 Filipe David Borba Manana <fdmanana@gmail.com> | ||
|  |  * | ||
|  |  * This program is free software; you can redistribute it and/or | ||
|  |  * modify it under the terms of the GNU General Public | ||
|  |  * License v2 as published by the Free Software Foundation. | ||
|  |  * | ||
|  |  * This program is distributed in the hope that it will be useful, | ||
|  |  * but WITHOUT ANY WARRANTY; without even the implied warranty of | ||
|  |  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU | ||
|  |  * General Public License for more details. | ||
|  |  */ | ||
|  | 
 | ||
|  | #include <crypto/hash.h>
 | ||
|  | #include <linux/err.h>
 | ||
|  | #include "hash.h"
 | ||
|  | 
 | ||
|  | static struct crypto_shash *tfm; | ||
|  | 
 | ||
|  | int __init btrfs_hash_init(void) | ||
|  | { | ||
|  | 	tfm = crypto_alloc_shash("crc32c", 0, 0); | ||
|  | 	if (IS_ERR(tfm)) | ||
|  | 		return PTR_ERR(tfm); | ||
|  | 
 | ||
|  | 	return 0; | ||
|  | } | ||
|  | 
 | ||
|  | void btrfs_hash_exit(void) | ||
|  | { | ||
|  | 	crypto_free_shash(tfm); | ||
|  | } | ||
|  | 
 | ||
|  | u32 btrfs_crc32c(u32 crc, const void *address, unsigned int length) | ||
|  | { | ||
|  | 	struct { | ||
|  | 		struct shash_desc shash; | ||
|  | 		char ctx[crypto_shash_descsize(tfm)]; | ||
|  | 	} desc; | ||
|  | 	int err; | ||
|  | 
 | ||
|  | 	desc.shash.tfm = tfm; | ||
|  | 	desc.shash.flags = 0; | ||
|  | 	*(u32 *)desc.ctx = crc; | ||
|  | 
 | ||
|  | 	err = crypto_shash_update(&desc.shash, address, length); | ||
|  | 	BUG_ON(err); | ||
|  | 
 | ||
|  | 	return *(u32 *)desc.ctx; | ||
|  | } |