root/crypto/lzo.c

DEFINITIONS

1. lzo_init
2. lzo_exit
3. lzo_compress
4. lzo_decompress
5. lzo_mod_init
6. lzo_mod_fini

/*
 * 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/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 = 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);

        vfree(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_list               = LIST_HEAD_INIT(alg.cra_list),
        .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");