linux/crypto/lz4.c
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   1/*
   2 * Cryptographic API.
   3 *
   4 * Copyright (c) 2013 Chanho Min <chanho.min@lge.com>
   5 *
   6 * This program is free software; you can redistribute it and/or modify it
   7 * under the terms of the GNU General Public License version 2 as published by
   8 * the Free Software Foundation.
   9 *
  10 * This program is distributed in the hope that it will be useful, but WITHOUT
  11 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  12 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
  13 * more details.
  14 *
  15 * You should have received a copy of the GNU General Public License along with
  16 * this program; if not, write to the Free Software Foundation, Inc., 51
  17 * Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
  18 *
  19 */
  20
  21#include <linux/init.h>
  22#include <linux/module.h>
  23#include <linux/crypto.h>
  24#include <linux/vmalloc.h>
  25#include <linux/lz4.h>
  26
  27struct lz4_ctx {
  28        void *lz4_comp_mem;
  29};
  30
  31static int lz4_init(struct crypto_tfm *tfm)
  32{
  33        struct lz4_ctx *ctx = crypto_tfm_ctx(tfm);
  34
  35        ctx->lz4_comp_mem = vmalloc(LZ4_MEM_COMPRESS);
  36        if (!ctx->lz4_comp_mem)
  37                return -ENOMEM;
  38
  39        return 0;
  40}
  41
  42static void lz4_exit(struct crypto_tfm *tfm)
  43{
  44        struct lz4_ctx *ctx = crypto_tfm_ctx(tfm);
  45        vfree(ctx->lz4_comp_mem);
  46}
  47
  48static int lz4_compress_crypto(struct crypto_tfm *tfm, const u8 *src,
  49                            unsigned int slen, u8 *dst, unsigned int *dlen)
  50{
  51        struct lz4_ctx *ctx = crypto_tfm_ctx(tfm);
  52        size_t tmp_len = *dlen;
  53        int err;
  54
  55        err = lz4_compress(src, slen, dst, &tmp_len, ctx->lz4_comp_mem);
  56
  57        if (err < 0)
  58                return -EINVAL;
  59
  60        *dlen = tmp_len;
  61        return 0;
  62}
  63
  64static int lz4_decompress_crypto(struct crypto_tfm *tfm, const u8 *src,
  65                              unsigned int slen, u8 *dst, unsigned int *dlen)
  66{
  67        int err;
  68        size_t tmp_len = *dlen;
  69        size_t __slen = slen;
  70
  71        err = lz4_decompress(src, &__slen, dst, tmp_len);
  72        if (err < 0)
  73                return -EINVAL;
  74
  75        *dlen = tmp_len;
  76        return err;
  77}
  78
  79static struct crypto_alg alg_lz4 = {
  80        .cra_name               = "lz4",
  81        .cra_flags              = CRYPTO_ALG_TYPE_COMPRESS,
  82        .cra_ctxsize            = sizeof(struct lz4_ctx),
  83        .cra_module             = THIS_MODULE,
  84        .cra_list               = LIST_HEAD_INIT(alg_lz4.cra_list),
  85        .cra_init               = lz4_init,
  86        .cra_exit               = lz4_exit,
  87        .cra_u                  = { .compress = {
  88        .coa_compress           = lz4_compress_crypto,
  89        .coa_decompress         = lz4_decompress_crypto } }
  90};
  91
  92static int __init lz4_mod_init(void)
  93{
  94        return crypto_register_alg(&alg_lz4);
  95}
  96
  97static void __exit lz4_mod_fini(void)
  98{
  99        crypto_unregister_alg(&alg_lz4);
 100}
 101
 102module_init(lz4_mod_init);
 103module_exit(lz4_mod_fini);
 104
 105MODULE_LICENSE("GPL");
 106MODULE_DESCRIPTION("LZ4 Compression Algorithm");
 107
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