lzo.c
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/*
* Cryptographic API.
*
* 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/mm.h>
#include <linux/lzo.h>
struct lzo_ctx {
void *lzo_comp_mem;
};
static int lzo_init(struct crypto_tfm *tfm)
{
struct lzo_ctx *ctx = crypto_tfm_ctx(tfm);
ctx->lzo_comp_mem = kmalloc(LZO1X_MEM_COMPRESS,
GFP_KERNEL | __GFP_NOWARN);
if (!ctx->lzo_comp_mem)
ctx->lzo_comp_mem = vmalloc(LZO1X_MEM_COMPRESS);
if (!ctx->lzo_comp_mem)
return -ENOMEM;
return 0;
}
static void lzo_exit(struct crypto_tfm *tfm)
{
struct lzo_ctx *ctx = crypto_tfm_ctx(tfm);
kvfree(ctx->lzo_comp_mem);
}
static int lzo_compress(struct crypto_tfm *tfm, const u8 *src,
unsigned int slen, u8 *dst, unsigned int *dlen)
{
struct lzo_ctx *ctx = crypto_tfm_ctx(tfm);
size_t tmp_len = *dlen; /* size_t(ulong) <-> uint on 64 bit */
int err;
err = lzo1x_1_compress(src, slen, dst, &tmp_len, ctx->lzo_comp_mem);
if (err != LZO_E_OK)
return -EINVAL;
*dlen = tmp_len;
return 0;
}
static int lzo_decompress(struct crypto_tfm *tfm, const u8 *src,
unsigned int slen, u8 *dst, unsigned int *dlen)
{
int err;
size_t tmp_len = *dlen; /* size_t(ulong) <-> uint on 64 bit */
err = lzo1x_decompress_safe(src, slen, dst, &tmp_len);
if (err != LZO_E_OK)
return -EINVAL;
*dlen = tmp_len;
return 0;
}
static struct crypto_alg alg = {
.cra_name = "lzo",
.cra_flags = CRYPTO_ALG_TYPE_COMPRESS,
.cra_ctxsize = sizeof(struct lzo_ctx),
.cra_module = THIS_MODULE,
.cra_init = lzo_init,
.cra_exit = lzo_exit,
.cra_u = { .compress = {
.coa_compress = lzo_compress,
.coa_decompress = lzo_decompress } }
};
static int __init lzo_mod_init(void)
{
return crypto_register_alg(&alg);
}
static void __exit lzo_mod_fini(void)
{
crypto_unregister_alg(&alg);
}
module_init(lzo_mod_init);
module_exit(lzo_mod_fini);
MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("LZO Compression Algorithm");
MODULE_ALIAS_CRYPTO("lzo");