crypto/lz4.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Cryptographic API.
   4  *
   5  * Copyright (c) 2013 Chanho Min <chanho.min@lge.com>
   6  */
   7
   8 #include <linux/init.h>
   9 #include <linux/module.h>
  10 #include <linux/crypto.h>
  11 #include <linux/vmalloc.h>
  12 #include <linux/lz4.h>
  13 #include <crypto/internal/scompress.h>
  14
  15 struct lz4_ctx {
  16         void *lz4_comp_mem;
  17 };
  18
  19 static void *lz4_alloc_ctx(struct crypto_scomp *tfm)
  20 {
  21         void *ctx;
  22
  23         ctx = vmalloc(LZ4_MEM_COMPRESS);
  24         if (!ctx)
  25                 return ERR_PTR(-ENOMEM);
  26
  27         return ctx;
  28 }
  29
  30 static int lz4_init(struct crypto_tfm *tfm)
  31 {
  32         struct lz4_ctx *ctx = crypto_tfm_ctx(tfm);
  33
  34         ctx->lz4_comp_mem = lz4_alloc_ctx(NULL);
  35         if (IS_ERR(ctx->lz4_comp_mem))
  36                 return -ENOMEM;
  37
  38         return 0;
  39 }
  40
  41 static void lz4_free_ctx(struct crypto_scomp *tfm, void *ctx)
  42 {
  43         vfree(ctx);
  44 }
  45
  46 static void lz4_exit(struct crypto_tfm *tfm)
  47 {
  48         struct lz4_ctx *ctx = crypto_tfm_ctx(tfm);
  49
  50         lz4_free_ctx(NULL, ctx->lz4_comp_mem);
  51 }
  52
  53 static int __lz4_compress_crypto(const u8 *src, unsigned int slen,
  54                                  u8 *dst, unsigned int *dlen, void *ctx)
  55 {
  56         int out_len = LZ4_compress_default(src, dst,
  57                 slen, *dlen, ctx);
  58
  59         if (!out_len)
  60                 return -EINVAL;
  61
  62         *dlen = out_len;
  63         return 0;
  64 }
  65
  66 static int lz4_scompress(struct crypto_scomp *tfm, const u8 *src,
  67                          unsigned int slen, u8 *dst, unsigned int *dlen,
  68                          void *ctx)
  69 {
  70         return __lz4_compress_crypto(src, slen, dst, dlen, ctx);
  71 }
  72
  73 static int lz4_compress_crypto(struct crypto_tfm *tfm, const u8 *src,
  74                                unsigned int slen, u8 *dst, unsigned int *dlen)
  75 {
  76         struct lz4_ctx *ctx = crypto_tfm_ctx(tfm);
  77
  78         return __lz4_compress_crypto(src, slen, dst, dlen, ctx->lz4_comp_mem);
  79 }
  80
  81 static int __lz4_decompress_crypto(const u8 *src, unsigned int slen,
  82                                    u8 *dst, unsigned int *dlen, void *ctx)
  83 {
  84         int out_len = LZ4_decompress_safe(src, dst, slen, *dlen);
  85
  86         if (out_len < 0)
  87                 return -EINVAL;
  88
  89         *dlen = out_len;
  90         return 0;
  91 }
  92
  93 static int lz4_sdecompress(struct crypto_scomp *tfm, const u8 *src,
  94                            unsigned int slen, u8 *dst, unsigned int *dlen,
  95                            void *ctx)
  96 {
  97         return __lz4_decompress_crypto(src, slen, dst, dlen, NULL);
  98 }
  99
 100 static int lz4_decompress_crypto(struct crypto_tfm *tfm, const u8 *src,
 101                                  unsigned int slen, u8 *dst,
 102                                  unsigned int *dlen)
 103 {
 104         return __lz4_decompress_crypto(src, slen, dst, dlen, NULL);
 105 }
 106
 107 static struct crypto_alg alg_lz4 = {
 108         .cra_name               = "lz4",
 109         .cra_driver_name        = "lz4-generic",
 110         .cra_flags              = CRYPTO_ALG_TYPE_COMPRESS,
 111         .cra_ctxsize            = sizeof(struct lz4_ctx),
 112         .cra_module             = THIS_MODULE,
 113         .cra_init               = lz4_init,
 114         .cra_exit               = lz4_exit,
 115         .cra_u                  = { .compress = {
 116         .coa_compress           = lz4_compress_crypto,
 117         .coa_decompress         = lz4_decompress_crypto } }
 118 };
 119
 120 static struct scomp_alg scomp = {
 121         .alloc_ctx              = lz4_alloc_ctx,
 122         .free_ctx               = lz4_free_ctx,
 123         .compress               = lz4_scompress,
 124         .decompress             = lz4_sdecompress,
 125         .base                   = {
 126                 .cra_name       = "lz4",
 127                 .cra_driver_name = "lz4-scomp",
 128                 .cra_module      = THIS_MODULE,
 129         }
 130 };
 131
 132 static int __init lz4_mod_init(void)
 133 {
 134         int ret;
 135
 136         ret = crypto_register_alg(&alg_lz4);
 137         if (ret)
 138                 return ret;
 139
 140         ret = crypto_register_scomp(&scomp);
 141         if (ret) {
 142                 crypto_unregister_alg(&alg_lz4);
 143                 return ret;
 144         }
 145
 146         return ret;
 147 }
 148
 149 static void __exit lz4_mod_fini(void)
 150 {
 151         crypto_unregister_alg(&alg_lz4);
 152         crypto_unregister_scomp(&scomp);
 153 }
 154
 155 subsys_initcall(lz4_mod_init);
 156 module_exit(lz4_mod_fini);
 157
 158 MODULE_LICENSE("GPL");
 159 MODULE_DESCRIPTION("LZ4 Compression Algorithm");
 160 MODULE_ALIAS_CRYPTO("lz4");