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         size_t tmp_len = *dlen;
  69         int err;
  70
  71         err = lz4hc_compress(src, slen, dst, &tmp_len, ctx);
  72
  73         if (err < 0)
  74                 return -EINVAL;
  75
  76         *dlen = tmp_len;
  77         return 0;
  78 }
  79
  80 static int lz4hc_scompress(struct crypto_scomp *tfm, const u8 *src,
  81                            unsigned int slen, u8 *dst, unsigned int *dlen,
  82                            void *ctx)
  83 {
  84         return __lz4hc_compress_crypto(src, slen, dst, dlen, ctx);
  85 }
  86
  87 static int lz4hc_compress_crypto(struct crypto_tfm *tfm, const u8 *src,
  88                                  unsigned int slen, u8 *dst,
  89                                  unsigned int *dlen)
  90 {
  91         struct lz4hc_ctx *ctx = crypto_tfm_ctx(tfm);
  92
  93         return __lz4hc_compress_crypto(src, slen, dst, dlen,
  94                                         ctx->lz4hc_comp_mem);
  95 }
  96
  97 static int __lz4hc_decompress_crypto(const u8 *src, unsigned int slen,
  98                                      u8 *dst, unsigned int *dlen, void *ctx)
  99 {
 100         int err;
 101         size_t tmp_len = *dlen;
 102         size_t __slen = slen;
 103
 104         err = lz4_decompress_unknownoutputsize(src, __slen, dst, &tmp_len);
 105         if (err < 0)
 106                 return -EINVAL;
 107
 108         *dlen = tmp_len;
 109         return err;
 110 }
 111
 112 static int lz4hc_sdecompress(struct crypto_scomp *tfm, const u8 *src,
 113                              unsigned int slen, u8 *dst, unsigned int *dlen,
 114                              void *ctx)
 115 {
 116         return __lz4hc_decompress_crypto(src, slen, dst, dlen, NULL);
 117 }
 118
 119 static int lz4hc_decompress_crypto(struct crypto_tfm *tfm, const u8 *src,
 120                                    unsigned int slen, u8 *dst,
 121                                    unsigned int *dlen)
 122 {
 123         return __lz4hc_decompress_crypto(src, slen, dst, dlen, NULL);
 124 }
 125
 126 static struct crypto_alg alg_lz4hc = {
 127         .cra_name               = "lz4hc",
 128         .cra_flags              = CRYPTO_ALG_TYPE_COMPRESS,
 129         .cra_ctxsize            = sizeof(struct lz4hc_ctx),
 130         .cra_module             = THIS_MODULE,
 131         .cra_list               = LIST_HEAD_INIT(alg_lz4hc.cra_list),
 132         .cra_init               = lz4hc_init,
 133         .cra_exit               = lz4hc_exit,
 134         .cra_u                  = { .compress = {
 135         .coa_compress           = lz4hc_compress_crypto,
 136         .coa_decompress         = lz4hc_decompress_crypto } }
 137 };
 138
 139 static struct scomp_alg scomp = {
 140         .alloc_ctx              = lz4hc_alloc_ctx,
 141         .free_ctx               = lz4hc_free_ctx,
 142         .compress               = lz4hc_scompress,
 143         .decompress             = lz4hc_sdecompress,
 144         .base                   = {
 145                 .cra_name       = "lz4hc",
 146                 .cra_driver_name = "lz4hc-scomp",
 147                 .cra_module      = THIS_MODULE,
 148         }
 149 };
 150
 151 static int __init lz4hc_mod_init(void)
 152 {
 153         int ret;
 154
 155         ret = crypto_register_alg(&alg_lz4hc);
 156         if (ret)
 157                 return ret;
 158
 159         ret = crypto_register_scomp(&scomp);
 160         if (ret) {
 161                 crypto_unregister_alg(&alg_lz4hc);
 162                 return ret;
 163         }
 164
 165         return ret;
 166 }
 167
 168 static void __exit lz4hc_mod_fini(void)
 169 {
 170         crypto_unregister_alg(&alg_lz4hc);
 171         crypto_unregister_scomp(&scomp);
 172 }
 173
 174 module_init(lz4hc_mod_init);
 175 module_exit(lz4hc_mod_fini);
 176
 177 MODULE_LICENSE("GPL");
 178 MODULE_DESCRIPTION("LZ4HC Compression Algorithm");
 179 MODULE_ALIAS_CRYPTO("lz4hc");