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/mm.h>
24#include <linux/lzo.h>
25
26struct lzo_ctx {
27    void *lzo_comp_mem;
28};
29
30static int lzo_init(struct crypto_tfm *tfm)
31{
32    struct lzo_ctx *ctx = crypto_tfm_ctx(tfm);
33
34    ctx->lzo_comp_mem = kmalloc(LZO1X_MEM_COMPRESS,
35                    GFP_KERNEL | __GFP_NOWARN | __GFP_REPEAT);
36    if (!ctx->lzo_comp_mem)
37        ctx->lzo_comp_mem = vmalloc(LZO1X_MEM_COMPRESS);
38    if (!ctx->lzo_comp_mem)
39        return -ENOMEM;
40
41    return 0;
42}
43
44static void lzo_exit(struct crypto_tfm *tfm)
45{
46    struct lzo_ctx *ctx = crypto_tfm_ctx(tfm);
47
48    kvfree(ctx->lzo_comp_mem);
49}
50
51static int lzo_compress(struct crypto_tfm *tfm, const u8 *src,
52                unsigned int slen, u8 *dst, unsigned int *dlen)
53{
54    struct lzo_ctx *ctx = crypto_tfm_ctx(tfm);
55    size_t tmp_len = *dlen; /* size_t(ulong) <-> uint on 64 bit */
56    int err;
57
58    err = lzo1x_1_compress(src, slen, dst, &tmp_len, ctx->lzo_comp_mem);
59
60    if (err != LZO_E_OK)
61        return -EINVAL;
62
63    *dlen = tmp_len;
64    return 0;
65}
66
67static int lzo_decompress(struct crypto_tfm *tfm, const u8 *src,
68                  unsigned int slen, u8 *dst, unsigned int *dlen)
69{
70    int err;
71    size_t tmp_len = *dlen; /* size_t(ulong) <-> uint on 64 bit */
72
73    err = lzo1x_decompress_safe(src, slen, dst, &tmp_len);
74
75    if (err != LZO_E_OK)
76        return -EINVAL;
77
78    *dlen = tmp_len;
79    return 0;
80
81}
82
83static struct crypto_alg alg = {
84    .cra_name = "lzo",
85    .cra_flags = CRYPTO_ALG_TYPE_COMPRESS,
86    .cra_ctxsize = sizeof(struct lzo_ctx),
87    .cra_module = THIS_MODULE,
88    .cra_init = lzo_init,
89    .cra_exit = lzo_exit,
90    .cra_u = { .compress = {
91    .coa_compress = lzo_compress,
92    .coa_decompress = lzo_decompress } }
93};
94
95static int __init lzo_mod_init(void)
96{
97    return crypto_register_alg(&alg);
98}
99
100static void __exit lzo_mod_fini(void)
101{
102    crypto_unregister_alg(&alg);
103}
104
105module_init(lzo_mod_init);
106module_exit(lzo_mod_fini);
107
108MODULE_LICENSE("GPL");
109MODULE_DESCRIPTION("LZO Compression Algorithm");
110

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