crypto/lz4.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
  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 #include <crypto/internal/scompress.h>
  27
  28 struct lz4_ctx {
  29         void *lz4_comp_mem;
  30 };
  31
  32 static void *lz4_alloc_ctx(struct crypto_scomp *tfm)
  33 {
  34         void *ctx;
  35
  36         ctx = vmalloc(LZ4_MEM_COMPRESS);
  37         if (!ctx)
  38                 return ERR_PTR(-ENOMEM);
  39
  40         return ctx;
  41 }
  42
  43 static int lz4_init(struct crypto_tfm *tfm)
  44 {
  45         struct lz4_ctx *ctx = crypto_tfm_ctx(tfm);
  46
  47         ctx->lz4_comp_mem = lz4_alloc_ctx(NULL);
  48         if (IS_ERR(ctx->lz4_comp_mem))
  49                 return -ENOMEM;
  50
  51         return 0;
  52 }
  53
  54 static void lz4_free_ctx(struct crypto_scomp *tfm, void *ctx)
  55 {
  56         vfree(ctx);
  57 }
  58
  59 static void lz4_exit(struct crypto_tfm *tfm)
  60 {
  61         struct lz4_ctx *ctx = crypto_tfm_ctx(tfm);
  62
  63         lz4_free_ctx(NULL, ctx->lz4_comp_mem);
  64 }
  65
  66 static int __lz4_compress_crypto(const u8 *src, unsigned int slen,
  67                                  u8 *dst, unsigned int *dlen, void *ctx)
  68 {
  69         int out_len = LZ4_compress_default(src, dst,
  70                 slen, *dlen, ctx);
  71
  72         if (!out_len)
  73                 return -EINVAL;
  74
  75         *dlen = out_len;
  76         return 0;
  77 }
  78
  79 static int lz4_scompress(struct crypto_scomp *tfm, const u8 *src,
  80                          unsigned int slen, u8 *dst, unsigned int *dlen,
  81                          void *ctx)
  82 {
  83         return __lz4_compress_crypto(src, slen, dst, dlen, ctx);
  84 }
  85
  86 static int lz4_compress_crypto(struct crypto_tfm *tfm, const u8 *src,
  87                                unsigned int slen, u8 *dst, unsigned int *dlen)
  88 {
  89         struct lz4_ctx *ctx = crypto_tfm_ctx(tfm);
  90
  91         return __lz4_compress_crypto(src, slen, dst, dlen, ctx->lz4_comp_mem);
  92 }
  93
  94 static int __lz4_decompress_crypto(const u8 *src, unsigned int slen,
  95                                    u8 *dst, unsigned int *dlen, void *ctx)
  96 {
  97         int out_len = LZ4_decompress_safe(src, dst, slen, *dlen);
  98
  99         if (out_len < 0)
 100                 return -EINVAL;
 101
 102         *dlen = out_len;
 103         return 0;
 104 }
 105
 106 static int lz4_sdecompress(struct crypto_scomp *tfm, const u8 *src,
 107                            unsigned int slen, u8 *dst, unsigned int *dlen,
 108                            void *ctx)
 109 {
 110         return __lz4_decompress_crypto(src, slen, dst, dlen, NULL);
 111 }
 112
 113 static int lz4_decompress_crypto(struct crypto_tfm *tfm, const u8 *src,
 114                                  unsigned int slen, u8 *dst,
 115                                  unsigned int *dlen)
 116 {
 117         return __lz4_decompress_crypto(src, slen, dst, dlen, NULL);
 118 }
 119
 120 static struct crypto_alg alg_lz4 = {
 121         .cra_name               = "lz4",
 122         .cra_flags              = CRYPTO_ALG_TYPE_COMPRESS,
 123         .cra_ctxsize            = sizeof(struct lz4_ctx),
 124         .cra_module             = THIS_MODULE,
 125         .cra_init               = lz4_init,
 126         .cra_exit               = lz4_exit,
 127         .cra_u                  = { .compress = {
 128         .coa_compress           = lz4_compress_crypto,
 129         .coa_decompress         = lz4_decompress_crypto } }
 130 };
 131
 132 static struct scomp_alg scomp = {
 133         .alloc_ctx              = lz4_alloc_ctx,
 134         .free_ctx               = lz4_free_ctx,
 135         .compress               = lz4_scompress,
 136         .decompress             = lz4_sdecompress,
 137         .base                   = {
 138                 .cra_name       = "lz4",
 139                 .cra_driver_name = "lz4-scomp",
 140                 .cra_module      = THIS_MODULE,
 141         }
 142 };
 143
 144 static int __init lz4_mod_init(void)
 145 {
 146         int ret;
 147
 148         ret = crypto_register_alg(&alg_lz4);
 149         if (ret)
 150                 return ret;
 151
 152         ret = crypto_register_scomp(&scomp);
 153         if (ret) {
 154                 crypto_unregister_alg(&alg_lz4);
 155                 return ret;
 156         }
 157
 158         return ret;
 159 }
 160
 161 static void __exit lz4_mod_fini(void)
 162 {
 163         crypto_unregister_alg(&alg_lz4);
 164         crypto_unregister_scomp(&scomp);
 165 }
 166
 167 subsys_initcall(lz4_mod_init);
 168 module_exit(lz4_mod_fini);
 169
 170 MODULE_LICENSE("GPL");
 171 MODULE_DESCRIPTION("LZ4 Compression Algorithm");
 172 MODULE_ALIAS_CRYPTO("lz4");