crypto/lzo.c

   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 #include <crypto/internal/scompress.h>
  26
  27 struct lzo_ctx {
  28         void *lzo_comp_mem;
  29 };
  30
  31 static void *lzo_alloc_ctx(struct crypto_scomp *tfm)
  32 {
  33         void *ctx;
  34
  35         ctx = kvmalloc(LZO1X_MEM_COMPRESS, GFP_KERNEL);
  36         if (!ctx)
  37                 return ERR_PTR(-ENOMEM);
  38
  39         return ctx;
  40 }
  41
  42 static int lzo_init(struct crypto_tfm *tfm)
  43 {
  44         struct lzo_ctx *ctx = crypto_tfm_ctx(tfm);
  45
  46         ctx->lzo_comp_mem = lzo_alloc_ctx(NULL);
  47         if (IS_ERR(ctx->lzo_comp_mem))
  48                 return -ENOMEM;
  49
  50         return 0;
  51 }
  52
  53 static void lzo_free_ctx(struct crypto_scomp *tfm, void *ctx)
  54 {
  55         kvfree(ctx);
  56 }
  57
  58 static void lzo_exit(struct crypto_tfm *tfm)
  59 {
  60         struct lzo_ctx *ctx = crypto_tfm_ctx(tfm);
  61
  62         lzo_free_ctx(NULL, ctx->lzo_comp_mem);
  63 }
  64
  65 static int __lzo_compress(const u8 *src, unsigned int slen,
  66                           u8 *dst, unsigned int *dlen, void *ctx)
  67 {
  68         size_t tmp_len = *dlen; /* size_t(ulong) <-> uint on 64 bit */
  69         int err;
  70
  71         err = lzo1x_1_compress(src, slen, dst, &tmp_len, ctx);
  72
  73         if (err != LZO_E_OK)
  74                 return -EINVAL;
  75
  76         *dlen = tmp_len;
  77         return 0;
  78 }
  79
  80 static int lzo_compress(struct crypto_tfm *tfm, const u8 *src,
  81                         unsigned int slen, u8 *dst, unsigned int *dlen)
  82 {
  83         struct lzo_ctx *ctx = crypto_tfm_ctx(tfm);
  84
  85         return __lzo_compress(src, slen, dst, dlen, ctx->lzo_comp_mem);
  86 }
  87
  88 static int lzo_scompress(struct crypto_scomp *tfm, const u8 *src,
  89                          unsigned int slen, u8 *dst, unsigned int *dlen,
  90                          void *ctx)
  91 {
  92         return __lzo_compress(src, slen, dst, dlen, ctx);
  93 }
  94
  95 static int __lzo_decompress(const u8 *src, unsigned int slen,
  96                             u8 *dst, unsigned int *dlen)
  97 {
  98         int err;
  99         size_t tmp_len = *dlen; /* size_t(ulong) <-> uint on 64 bit */
 100
 101         err = lzo1x_decompress_safe(src, slen, dst, &tmp_len);
 102
 103         if (err != LZO_E_OK)
 104                 return -EINVAL;
 105
 106         *dlen = tmp_len;
 107         return 0;
 108 }
 109
 110 static int lzo_decompress(struct crypto_tfm *tfm, const u8 *src,
 111                           unsigned int slen, u8 *dst, unsigned int *dlen)
 112 {
 113         return __lzo_decompress(src, slen, dst, dlen);
 114 }
 115
 116 static int lzo_sdecompress(struct crypto_scomp *tfm, const u8 *src,
 117                            unsigned int slen, u8 *dst, unsigned int *dlen,
 118                            void *ctx)
 119 {
 120         return __lzo_decompress(src, slen, dst, dlen);
 121 }
 122
 123 static struct crypto_alg alg = {
 124         .cra_name               = "lzo",
 125         .cra_flags              = CRYPTO_ALG_TYPE_COMPRESS,
 126         .cra_ctxsize            = sizeof(struct lzo_ctx),
 127         .cra_module             = THIS_MODULE,
 128         .cra_init               = lzo_init,
 129         .cra_exit               = lzo_exit,
 130         .cra_u                  = { .compress = {
 131         .coa_compress           = lzo_compress,
 132         .coa_decompress         = lzo_decompress } }
 133 };
 134
 135 static struct scomp_alg scomp = {
 136         .alloc_ctx              = lzo_alloc_ctx,
 137         .free_ctx               = lzo_free_ctx,
 138         .compress               = lzo_scompress,
 139         .decompress             = lzo_sdecompress,
 140         .base                   = {
 141                 .cra_name       = "lzo",
 142                 .cra_driver_name = "lzo-scomp",
 143                 .cra_module      = THIS_MODULE,
 144         }
 145 };
 146
 147 static int __init lzo_mod_init(void)
 148 {
 149         int ret;
 150
 151         ret = crypto_register_alg(&alg);
 152         if (ret)
 153                 return ret;
 154
 155         ret = crypto_register_scomp(&scomp);
 156         if (ret) {
 157                 crypto_unregister_alg(&alg);
 158                 return ret;
 159         }
 160
 161         return ret;
 162 }
 163
 164 static void __exit lzo_mod_fini(void)
 165 {
 166         crypto_unregister_alg(&alg);
 167         crypto_unregister_scomp(&scomp);
 168 }
 169
 170 subsys_initcall(lzo_mod_init);
 171 module_exit(lzo_mod_fini);
 172
 173 MODULE_LICENSE("GPL");
 174 MODULE_DESCRIPTION("LZO Compression Algorithm");
 175 MODULE_ALIAS_CRYPTO("lzo");