Root/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
27struct lz4_ctx {
28    void *lz4_comp_mem;
29};
30
31static int lz4_init(struct crypto_tfm *tfm)
32{
33    struct lz4_ctx *ctx = crypto_tfm_ctx(tfm);
34
35    ctx->lz4_comp_mem = vmalloc(LZ4_MEM_COMPRESS);
36    if (!ctx->lz4_comp_mem)
37        return -ENOMEM;
38
39    return 0;
40}
41
42static void lz4_exit(struct crypto_tfm *tfm)
43{
44    struct lz4_ctx *ctx = crypto_tfm_ctx(tfm);
45    vfree(ctx->lz4_comp_mem);
46}
47
48static int lz4_compress_crypto(struct crypto_tfm *tfm, const u8 *src,
49                unsigned int slen, u8 *dst, unsigned int *dlen)
50{
51    struct lz4_ctx *ctx = crypto_tfm_ctx(tfm);
52    size_t tmp_len = *dlen;
53    int err;
54
55    err = lz4_compress(src, slen, dst, &tmp_len, ctx->lz4_comp_mem);
56
57    if (err < 0)
58        return -EINVAL;
59
60    *dlen = tmp_len;
61    return 0;
62}
63
64static int lz4_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
79static struct crypto_alg alg_lz4 = {
80    .cra_name = "lz4",
81    .cra_flags = CRYPTO_ALG_TYPE_COMPRESS,
82    .cra_ctxsize = sizeof(struct lz4_ctx),
83    .cra_module = THIS_MODULE,
84    .cra_list = LIST_HEAD_INIT(alg_lz4.cra_list),
85    .cra_init = lz4_init,
86    .cra_exit = lz4_exit,
87    .cra_u = { .compress = {
88    .coa_compress = lz4_compress_crypto,
89    .coa_decompress = lz4_decompress_crypto } }
90};
91
92static int __init lz4_mod_init(void)
93{
94    return crypto_register_alg(&alg_lz4);
95}
96
97static void __exit lz4_mod_fini(void)
98{
99    crypto_unregister_alg(&alg_lz4);
100}
101
102module_init(lz4_mod_init);
103module_exit(lz4_mod_fini);
104
105MODULE_LICENSE("GPL");
106MODULE_DESCRIPTION("LZ4 Compression Algorithm");
107

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