crypto/lz4hc.c

   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 #include <linux/init.h>
  21 #include <linux/module.h>
  22 #include <linux/crypto.h>
  23 #include <linux/vmalloc.h>
  24 #include <linux/lz4.h>
  25
  26 struct lz4hc_ctx {
  27         void *lz4hc_comp_mem;
  28 };
  29
  30 static int lz4hc_init(struct crypto_tfm *tfm)
  31 {
  32         struct lz4hc_ctx *ctx = crypto_tfm_ctx(tfm);
  33
  34         ctx->lz4hc_comp_mem = vmalloc(LZ4HC_MEM_COMPRESS);
  35         if (!ctx->lz4hc_comp_mem)
  36                 return -ENOMEM;
  37
  38         return 0;
  39 }
  40
  41 static void lz4hc_exit(struct crypto_tfm *tfm)
  42 {
  43         struct lz4hc_ctx *ctx = crypto_tfm_ctx(tfm);
  44
  45         vfree(ctx->lz4hc_comp_mem);
  46 }
  47
  48 static int lz4hc_compress_crypto(struct crypto_tfm *tfm, const u8 *src,
  49                             unsigned int slen, u8 *dst, unsigned int *dlen)
  50 {
  51         struct lz4hc_ctx *ctx = crypto_tfm_ctx(tfm);
  52         size_t tmp_len = *dlen;
  53         int err;
  54
  55         err = lz4hc_compress(src, slen, dst, &tmp_len, ctx->lz4hc_comp_mem);
  56
  57         if (err < 0)
  58                 return -EINVAL;
  59
  60         *dlen = tmp_len;
  61         return 0;
  62 }
  63
  64 static int lz4hc_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_unknownoutputsize(src, __slen, dst, &tmp_len);
  72         if (err < 0)
  73                 return -EINVAL;
  74
  75         *dlen = tmp_len;
  76         return err;
  77 }
  78
  79 static struct crypto_alg alg_lz4hc = {
  80         .cra_name               = "lz4hc",
  81         .cra_flags              = CRYPTO_ALG_TYPE_COMPRESS,
  82         .cra_ctxsize            = sizeof(struct lz4hc_ctx),
  83         .cra_module             = THIS_MODULE,
  84         .cra_list               = LIST_HEAD_INIT(alg_lz4hc.cra_list),
  85         .cra_init               = lz4hc_init,
  86         .cra_exit               = lz4hc_exit,
  87         .cra_u                  = { .compress = {
  88         .coa_compress           = lz4hc_compress_crypto,
  89         .coa_decompress         = lz4hc_decompress_crypto } }
  90 };
  91
  92 static int __init lz4hc_mod_init(void)
  93 {
  94         return crypto_register_alg(&alg_lz4hc);
  95 }
  96
  97 static void __exit lz4hc_mod_fini(void)
  98 {
  99         crypto_unregister_alg(&alg_lz4hc);
 100 }
 101
 102 module_init(lz4hc_mod_init);
 103 module_exit(lz4hc_mod_fini);
 104
 105 MODULE_LICENSE("GPL");
 106 MODULE_DESCRIPTION("LZ4HC Compression Algorithm");