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
26 struct lz4hc_ctx {
27 void *lz4hc_comp_mem;
28 };
29
lz4hc_init(struct crypto_tfm * tfm)30 static int lz4hc_init(struct crypto_tfm *tfm)
31 {
32 struct lz4hc_ctx *ctx = crypto_tfm_ctx(tfm);
33
34 ctx->lz4hc_comp_mem = vmalloc(LZ4HC_MEM_COMPRESS);
35 if (!ctx->lz4hc_comp_mem)
36 return -ENOMEM;
37
38 return 0;
39 }
40
lz4hc_exit(struct crypto_tfm * tfm)41 static void lz4hc_exit(struct crypto_tfm *tfm)
42 {
43 struct lz4hc_ctx *ctx = crypto_tfm_ctx(tfm);
44
45 vfree(ctx->lz4hc_comp_mem);
46 }
47
lz4hc_compress_crypto(struct crypto_tfm * tfm,const u8 * src,unsigned int slen,u8 * dst,unsigned int * dlen)48 static int lz4hc_compress_crypto(struct crypto_tfm *tfm, const u8 *src,
49 unsigned int slen, u8 *dst, unsigned int *dlen)
50 {
51 struct lz4hc_ctx *ctx = crypto_tfm_ctx(tfm);
52 size_t tmp_len = *dlen;
53 int err;
54
55 err = lz4hc_compress(src, slen, dst, &tmp_len, ctx->lz4hc_comp_mem);
56
57 if (err < 0)
58 return -EINVAL;
59
60 *dlen = tmp_len;
61 return 0;
62 }
63
lz4hc_decompress_crypto(struct crypto_tfm * tfm,const u8 * src,unsigned int slen,u8 * dst,unsigned int * dlen)64 static int lz4hc_decompress_crypto(struct crypto_tfm *tfm, const u8 *src,
65 unsigned int slen, u8 *dst, unsigned int *dlen)
66 {
67 int err;
68 size_t tmp_len = *dlen;
69 size_t __slen = slen;
70
71 err = lz4_decompress_unknownoutputsize(src, __slen, dst, &tmp_len);
72 if (err < 0)
73 return -EINVAL;
74
75 *dlen = tmp_len;
76 return err;
77 }
78
79 static struct crypto_alg alg_lz4hc = {
80 .cra_name = "lz4hc",
81 .cra_flags = CRYPTO_ALG_TYPE_COMPRESS,
82 .cra_ctxsize = sizeof(struct lz4hc_ctx),
83 .cra_module = THIS_MODULE,
84 .cra_list = LIST_HEAD_INIT(alg_lz4hc.cra_list),
85 .cra_init = lz4hc_init,
86 .cra_exit = lz4hc_exit,
87 .cra_u = { .compress = {
88 .coa_compress = lz4hc_compress_crypto,
89 .coa_decompress = lz4hc_decompress_crypto } }
90 };
91
lz4hc_mod_init(void)92 static int __init lz4hc_mod_init(void)
93 {
94 return crypto_register_alg(&alg_lz4hc);
95 }
96
lz4hc_mod_fini(void)97 static void __exit lz4hc_mod_fini(void)
98 {
99 crypto_unregister_alg(&alg_lz4hc);
100 }
101
102 module_init(lz4hc_mod_init);
103 module_exit(lz4hc_mod_fini);
104
105 MODULE_LICENSE("GPL");
106 MODULE_DESCRIPTION("LZ4HC Compression Algorithm");
107 MODULE_ALIAS_CRYPTO("lz4hc");
108