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 #include <crypto/internal/scompress.h>
  26
  27 struct lz4hc_ctx {
  28         void *lz4hc_comp_mem;
  29 };
  30
  31 static void *lz4hc_alloc_ctx(struct crypto_scomp *tfm)
  32 {
  33         void *ctx;
  34
  35         ctx = vmalloc(LZ4HC_MEM_COMPRESS);
  36         if (!ctx)
  37                 return ERR_PTR(-ENOMEM);
  38
  39         return ctx;
  40 }
  41
  42 static int lz4hc_init(struct crypto_tfm *tfm)
  43 {
  44         struct lz4hc_ctx *ctx = crypto_tfm_ctx(tfm);
  45
  46         ctx->lz4hc_comp_mem = lz4hc_alloc_ctx(NULL);
  47         if (IS_ERR(ctx->lz4hc_comp_mem))
  48                 return -ENOMEM;
  49
  50         return 0;
  51 }
  52
  53 static void lz4hc_free_ctx(struct crypto_scomp *tfm, void *ctx)
  54 {
  55         vfree(ctx);
  56 }
  57
  58 static void lz4hc_exit(struct crypto_tfm *tfm)
  59 {
  60         struct lz4hc_ctx *ctx = crypto_tfm_ctx(tfm);
  61
  62         lz4hc_free_ctx(NULL, ctx->lz4hc_comp_mem);
  63 }
  64
  65 static int __lz4hc_compress_crypto(const u8 *src, unsigned int slen,
  66                                    u8 *dst, unsigned int *dlen, void *ctx)
  67 {
  68         int out_len = LZ4_compress_HC(src, dst, slen,
  69                 *dlen, LZ4HC_DEFAULT_CLEVEL, ctx);
  70
  71         if (!out_len)
  72                 return -EINVAL;
  73
  74         *dlen = out_len;
  75         return 0;
  76 }
  77
  78 static int lz4hc_scompress(struct crypto_scomp *tfm, const u8 *src,
  79                            unsigned int slen, u8 *dst, unsigned int *dlen,
  80                            void *ctx)
  81 {
  82         return __lz4hc_compress_crypto(src, slen, dst, dlen, ctx);
  83 }
  84
  85 static int lz4hc_compress_crypto(struct crypto_tfm *tfm, const u8 *src,
  86                                  unsigned int slen, u8 *dst,
  87                                  unsigned int *dlen)
  88 {
  89         struct lz4hc_ctx *ctx = crypto_tfm_ctx(tfm);
  90
  91         return __lz4hc_compress_crypto(src, slen, dst, dlen,
  92                                         ctx->lz4hc_comp_mem);
  93 }
  94
  95 static int __lz4hc_decompress_crypto(const u8 *src, unsigned int slen,
  96                                      u8 *dst, unsigned int *dlen, void *ctx)
  97 {
  98         int out_len = LZ4_decompress_safe(src, dst, slen, *dlen);
  99
 100         if (out_len < 0)
 101                 return -EINVAL;
 102
 103         *dlen = out_len;
 104         return 0;
 105 }
 106
 107 static int lz4hc_sdecompress(struct crypto_scomp *tfm, const u8 *src,
 108                              unsigned int slen, u8 *dst, unsigned int *dlen,
 109                              void *ctx)
 110 {
 111         return __lz4hc_decompress_crypto(src, slen, dst, dlen, NULL);
 112 }
 113
 114 static int lz4hc_decompress_crypto(struct crypto_tfm *tfm, const u8 *src,
 115                                    unsigned int slen, u8 *dst,
 116                                    unsigned int *dlen)
 117 {
 118         return __lz4hc_decompress_crypto(src, slen, dst, dlen, NULL);
 119 }
 120
 121 static struct crypto_alg alg_lz4hc = {
 122         .cra_name               = "lz4hc",
 123         .cra_flags              = CRYPTO_ALG_TYPE_COMPRESS,
 124         .cra_ctxsize            = sizeof(struct lz4hc_ctx),
 125         .cra_module             = THIS_MODULE,
 126         .cra_init               = lz4hc_init,
 127         .cra_exit               = lz4hc_exit,
 128         .cra_u                  = { .compress = {
 129         .coa_compress           = lz4hc_compress_crypto,
 130         .coa_decompress         = lz4hc_decompress_crypto } }
 131 };
 132
 133 static struct scomp_alg scomp = {
 134         .alloc_ctx              = lz4hc_alloc_ctx,
 135         .free_ctx               = lz4hc_free_ctx,
 136         .compress               = lz4hc_scompress,
 137         .decompress             = lz4hc_sdecompress,
 138         .base                   = {
 139                 .cra_name       = "lz4hc",
 140                 .cra_driver_name = "lz4hc-scomp",
 141                 .cra_module      = THIS_MODULE,
 142         }
 143 };
 144
 145 static int __init lz4hc_mod_init(void)
 146 {
 147         int ret;
 148
 149         ret = crypto_register_alg(&alg_lz4hc);
 150         if (ret)
 151                 return ret;
 152
 153         ret = crypto_register_scomp(&scomp);
 154         if (ret) {
 155                 crypto_unregister_alg(&alg_lz4hc);
 156                 return ret;
 157         }
 158
 159         return ret;
 160 }
 161
 162 static void __exit lz4hc_mod_fini(void)
 163 {
 164         crypto_unregister_alg(&alg_lz4hc);
 165         crypto_unregister_scomp(&scomp);
 166 }
 167
 168 module_init(lz4hc_mod_init);
 169 module_exit(lz4hc_mod_fini);
 170
 171 MODULE_LICENSE("GPL");
 172 MODULE_DESCRIPTION("LZ4HC Compression Algorithm");
 173 MODULE_ALIAS_CRYPTO("lz4hc");