crypto/lzo.c

   1 /*
   2  * Cryptographic API.
   3  *
   4  * This program is free software; you can redistribute it and/or modify it
   5  * under the terms of the GNU General Public License version 2 as published by
   6  * the Free Software Foundation.
   7  *
   8  * This program is distributed in the hope that it will be useful, but WITHOUT
   9  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  10  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
  11  * more details.
  12  *
  13  * You should have received a copy of the GNU General Public License along with
  14  * this program; if not, write to the Free Software Foundation, Inc., 51
  15  * Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
  16  *
  17  */
  18
  19 #include <linux/init.h>
  20 #include <linux/module.h>
  21 #include <linux/crypto.h>
  22 #include <linux/vmalloc.h>
  23 #include <linux/mm.h>
  24 #include <linux/lzo.h>
  25
  26 struct lzo_ctx {
  27         void *lzo_comp_mem;
  28 };
  29
  30 static int lzo_init(struct crypto_tfm *tfm)
  31 {
  32         struct lzo_ctx *ctx = crypto_tfm_ctx(tfm);
  33
  34         ctx->lzo_comp_mem = kmalloc(LZO1X_MEM_COMPRESS,
  35                                     GFP_KERNEL | __GFP_NOWARN | __GFP_REPEAT);
  36         if (!ctx->lzo_comp_mem)
  37                 ctx->lzo_comp_mem = vmalloc(LZO1X_MEM_COMPRESS);
  38         if (!ctx->lzo_comp_mem)
  39                 return -ENOMEM;
  40
  41         return 0;
  42 }
  43
  44 static void lzo_exit(struct crypto_tfm *tfm)
  45 {
  46         struct lzo_ctx *ctx = crypto_tfm_ctx(tfm);
  47
  48         kvfree(ctx->lzo_comp_mem);
  49 }
  50
  51 static int lzo_compress(struct crypto_tfm *tfm, const u8 *src,
  52                             unsigned int slen, u8 *dst, unsigned int *dlen)
  53 {
  54         struct lzo_ctx *ctx = crypto_tfm_ctx(tfm);
  55         size_t tmp_len = *dlen; /* size_t(ulong) <-> uint on 64 bit */
  56         int err;
  57
  58         err = lzo1x_1_compress(src, slen, dst, &tmp_len, ctx->lzo_comp_mem);
  59
  60         if (err != LZO_E_OK)
  61                 return -EINVAL;
  62
  63         *dlen = tmp_len;
  64         return 0;
  65 }
  66
  67 static int lzo_decompress(struct crypto_tfm *tfm, const u8 *src,
  68                               unsigned int slen, u8 *dst, unsigned int *dlen)
  69 {
  70         int err;
  71         size_t tmp_len = *dlen; /* size_t(ulong) <-> uint on 64 bit */
  72
  73         err = lzo1x_decompress_safe(src, slen, dst, &tmp_len);
  74
  75         if (err != LZO_E_OK)
  76                 return -EINVAL;
  77
  78         *dlen = tmp_len;
  79         return 0;
  80
  81 }
  82
  83 static struct crypto_alg alg = {
  84         .cra_name               = "lzo",
  85         .cra_flags              = CRYPTO_ALG_TYPE_COMPRESS,
  86         .cra_ctxsize            = sizeof(struct lzo_ctx),
  87         .cra_module             = THIS_MODULE,
  88         .cra_init               = lzo_init,
  89         .cra_exit               = lzo_exit,
  90         .cra_u                  = { .compress = {
  91         .coa_compress           = lzo_compress,
  92         .coa_decompress         = lzo_decompress } }
  93 };
  94
  95 static int __init lzo_mod_init(void)
  96 {
  97         return crypto_register_alg(&alg);
  98 }
  99
 100 static void __exit lzo_mod_fini(void)
 101 {
 102         crypto_unregister_alg(&alg);
 103 }
 104
 105 module_init(lzo_mod_init);
 106 module_exit(lzo_mod_fini);
 107
 108 MODULE_LICENSE("GPL");
 109 MODULE_DESCRIPTION("LZO Compression Algorithm");