alistair23-linux/crypto/lz4.c
KOVACS Krisztian d801ab204b crypto: lz4,lz4hc - fix decompression
The lz4 library has two functions for decompression, with slightly
different signatures and behaviour. The lz4_decompress_crypto() function
seemed to be using the one that assumes that the decompressed length is
known in advance.

This patch switches to the other decompression function and makes sure
that the length of the decompressed output is properly returned to the
caller.

The same issue was present in the lz4hc algorithm.

Coincidentally, this change also makes very basic lz4 and lz4hc
compression tests in testmgr pass.

Signed-off-by: KOVACS Krisztian <hidden@sch.bme.hu>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2014-08-29 21:46:35 +08:00

107 lines
2.5 KiB
C

/*
* Cryptographic API.
*
* Copyright (c) 2013 Chanho Min <chanho.min@lge.com>
*
* This program is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 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.
*
* You should have received a copy of the GNU General Public License along with
* this program; if not, write to the Free Software Foundation, Inc., 51
* Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*
*/
#include <linux/init.h>
#include <linux/module.h>
#include <linux/crypto.h>
#include <linux/vmalloc.h>
#include <linux/lz4.h>
struct lz4_ctx {
void *lz4_comp_mem;
};
static int lz4_init(struct crypto_tfm *tfm)
{
struct lz4_ctx *ctx = crypto_tfm_ctx(tfm);
ctx->lz4_comp_mem = vmalloc(LZ4_MEM_COMPRESS);
if (!ctx->lz4_comp_mem)
return -ENOMEM;
return 0;
}
static void lz4_exit(struct crypto_tfm *tfm)
{
struct lz4_ctx *ctx = crypto_tfm_ctx(tfm);
vfree(ctx->lz4_comp_mem);
}
static int lz4_compress_crypto(struct crypto_tfm *tfm, const u8 *src,
unsigned int slen, u8 *dst, unsigned int *dlen)
{
struct lz4_ctx *ctx = crypto_tfm_ctx(tfm);
size_t tmp_len = *dlen;
int err;
err = lz4_compress(src, slen, dst, &tmp_len, ctx->lz4_comp_mem);
if (err < 0)
return -EINVAL;
*dlen = tmp_len;
return 0;
}
static int lz4_decompress_crypto(struct crypto_tfm *tfm, const u8 *src,
unsigned int slen, u8 *dst, unsigned int *dlen)
{
int err;
size_t tmp_len = *dlen;
size_t __slen = slen;
err = lz4_decompress_unknownoutputsize(src, __slen, dst, &tmp_len);
if (err < 0)
return -EINVAL;
*dlen = tmp_len;
return err;
}
static struct crypto_alg alg_lz4 = {
.cra_name = "lz4",
.cra_flags = CRYPTO_ALG_TYPE_COMPRESS,
.cra_ctxsize = sizeof(struct lz4_ctx),
.cra_module = THIS_MODULE,
.cra_list = LIST_HEAD_INIT(alg_lz4.cra_list),
.cra_init = lz4_init,
.cra_exit = lz4_exit,
.cra_u = { .compress = {
.coa_compress = lz4_compress_crypto,
.coa_decompress = lz4_decompress_crypto } }
};
static int __init lz4_mod_init(void)
{
return crypto_register_alg(&alg_lz4);
}
static void __exit lz4_mod_fini(void)
{
crypto_unregister_alg(&alg_lz4);
}
module_init(lz4_mod_init);
module_exit(lz4_mod_fini);
MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("LZ4 Compression Algorithm");