linux/crypto/lzo.c
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   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
  26struct lzo_ctx {
  27        void *lzo_comp_mem;
  28};
  29
  30static 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);
  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
  44static 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
  51static 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
  67static 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
  83static 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
  95static int __init lzo_mod_init(void)
  96{
  97        return crypto_register_alg(&alg);
  98}
  99
 100static void __exit lzo_mod_fini(void)
 101{
 102        crypto_unregister_alg(&alg);
 103}
 104
 105module_init(lzo_mod_init);
 106module_exit(lzo_mod_fini);
 107
 108MODULE_LICENSE("GPL");
 109MODULE_DESCRIPTION("LZO Compression Algorithm");
 110MODULE_ALIAS_CRYPTO("lzo");
 111