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         size_t tmp_len = *dlen;
  70         int err;
  71
  72         err = lz4_compress(src, slen, dst, &tmp_len, ctx);
  73
  74         if (err < 0)
  75                 return -EINVAL;
  76
  77         *dlen = tmp_len;
  78         return 0;
  79 }
  80
  81 static int lz4_scompress(struct crypto_scomp *tfm, const u8 *src,
  82                          unsigned int slen, u8 *dst, unsigned int *dlen,
  83                          void *ctx)
  84 {
  85         return __lz4_compress_crypto(src, slen, dst, dlen, ctx);
  86 }
  87
  88 static int lz4_compress_crypto(struct crypto_tfm *tfm, const u8 *src,
  89                                unsigned int slen, u8 *dst, unsigned int *dlen)
  90 {
  91         struct lz4_ctx *ctx = crypto_tfm_ctx(tfm);
  92
  93         return __lz4_compress_crypto(src, slen, dst, dlen, ctx->lz4_comp_mem);
  94 }
  95
  96 static int __lz4_decompress_crypto(const u8 *src, unsigned int slen,
  97                                    u8 *dst, unsigned int *dlen, void *ctx)
  98 {
  99         int err;
 100         size_t tmp_len = *dlen;
 101         size_t __slen = slen;
 102
 103         err = lz4_decompress_unknownoutputsize(src, __slen, dst, &tmp_len);
 104         if (err < 0)
 105                 return -EINVAL;
 106
 107         *dlen = tmp_len;
 108         return err;
 109 }
 110
 111 static int lz4_sdecompress(struct crypto_scomp *tfm, const u8 *src,
 112                            unsigned int slen, u8 *dst, unsigned int *dlen,
 113                            void *ctx)
 114 {
 115         return __lz4_decompress_crypto(src, slen, dst, dlen, NULL);
 116 }
 117
 118 static int lz4_decompress_crypto(struct crypto_tfm *tfm, const u8 *src,
 119                                  unsigned int slen, u8 *dst,
 120                                  unsigned int *dlen)
 121 {
 122         return __lz4_decompress_crypto(src, slen, dst, dlen, NULL);
 123 }
 124
 125 static struct crypto_alg alg_lz4 = {
 126         .cra_name               = "lz4",
 127         .cra_flags              = CRYPTO_ALG_TYPE_COMPRESS,
 128         .cra_ctxsize            = sizeof(struct lz4_ctx),
 129         .cra_module             = THIS_MODULE,
 130         .cra_list               = LIST_HEAD_INIT(alg_lz4.cra_list),
 131         .cra_init               = lz4_init,
 132         .cra_exit               = lz4_exit,
 133         .cra_u                  = { .compress = {
 134         .coa_compress           = lz4_compress_crypto,
 135         .coa_decompress         = lz4_decompress_crypto } }
 136 };
 137
 138 static struct scomp_alg scomp = {
 139         .alloc_ctx              = lz4_alloc_ctx,
 140         .free_ctx               = lz4_free_ctx,
 141         .compress               = lz4_scompress,
 142         .decompress             = lz4_sdecompress,
 143         .base                   = {
 144                 .cra_name       = "lz4",
 145                 .cra_driver_name = "lz4-scomp",
 146                 .cra_module      = THIS_MODULE,
 147         }
 148 };
 149
 150 static int __init lz4_mod_init(void)
 151 {
 152         int ret;
 153
 154         ret = crypto_register_alg(&alg_lz4);
 155         if (ret)
 156                 return ret;
 157
 158         ret = crypto_register_scomp(&scomp);
 159         if (ret) {
 160                 crypto_unregister_alg(&alg_lz4);
 161                 return ret;
 162         }
 163
 164         return ret;
 165 }
 166
 167 static void __exit lz4_mod_fini(void)
 168 {
 169         crypto_unregister_alg(&alg_lz4);
 170         crypto_unregister_scomp(&scomp);
 171 }
 172
 173 module_init(lz4_mod_init);
 174 module_exit(lz4_mod_fini);
 175
 176 MODULE_LICENSE("GPL");
 177 MODULE_DESCRIPTION("LZ4 Compression Algorithm");
 178 MODULE_ALIAS_CRYPTO("lz4");