Root/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/lzo.h>
24
25struct lzo_ctx {
26    void *lzo_comp_mem;
27};
28
29static int lzo_init(struct crypto_tfm *tfm)
30{
31    struct lzo_ctx *ctx = crypto_tfm_ctx(tfm);
32
33    ctx->lzo_comp_mem = vmalloc(LZO1X_MEM_COMPRESS);
34    if (!ctx->lzo_comp_mem)
35        return -ENOMEM;
36
37    return 0;
38}
39
40static void lzo_exit(struct crypto_tfm *tfm)
41{
42    struct lzo_ctx *ctx = crypto_tfm_ctx(tfm);
43
44    vfree(ctx->lzo_comp_mem);
45}
46
47static int lzo_compress(struct crypto_tfm *tfm, const u8 *src,
48                unsigned int slen, u8 *dst, unsigned int *dlen)
49{
50    struct lzo_ctx *ctx = crypto_tfm_ctx(tfm);
51    size_t tmp_len = *dlen; /* size_t(ulong) <-> uint on 64 bit */
52    int err;
53
54    err = lzo1x_1_compress(src, slen, dst, &tmp_len, ctx->lzo_comp_mem);
55
56    if (err != LZO_E_OK)
57        return -EINVAL;
58
59    *dlen = tmp_len;
60    return 0;
61}
62
63static int lzo_decompress(struct crypto_tfm *tfm, const u8 *src,
64                  unsigned int slen, u8 *dst, unsigned int *dlen)
65{
66    int err;
67    size_t tmp_len = *dlen; /* size_t(ulong) <-> uint on 64 bit */
68
69    err = lzo1x_decompress_safe(src, slen, dst, &tmp_len);
70
71    if (err != LZO_E_OK)
72        return -EINVAL;
73
74    *dlen = tmp_len;
75    return 0;
76
77}
78
79static struct crypto_alg alg = {
80    .cra_name = "lzo",
81    .cra_flags = CRYPTO_ALG_TYPE_COMPRESS,
82    .cra_ctxsize = sizeof(struct lzo_ctx),
83    .cra_module = THIS_MODULE,
84    .cra_init = lzo_init,
85    .cra_exit = lzo_exit,
86    .cra_u = { .compress = {
87    .coa_compress = lzo_compress,
88    .coa_decompress = lzo_decompress } }
89};
90
91static int __init lzo_mod_init(void)
92{
93    return crypto_register_alg(&alg);
94}
95
96static void __exit lzo_mod_fini(void)
97{
98    crypto_unregister_alg(&alg);
99}
100
101module_init(lzo_mod_init);
102module_exit(lzo_mod_fini);
103
104MODULE_LICENSE("GPL");
105MODULE_DESCRIPTION("LZO Compression Algorithm");
106

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