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#include <crypto/internal/scompress.h>
26
27struct lz4hc_ctx {
28 void *lz4hc_comp_mem;
29};
30
31static void *lz4hc_alloc_ctx(struct crypto_scomp *tfm)
32{
33 void *ctx;
34
35 ctx = vmalloc(LZ4HC_MEM_COMPRESS);
36 if (!ctx)
37 return ERR_PTR(-ENOMEM);
38
39 return ctx;
40}
41
42static int lz4hc_init(struct crypto_tfm *tfm)
43{
44 struct lz4hc_ctx *ctx = crypto_tfm_ctx(tfm);
45
46 ctx->lz4hc_comp_mem = lz4hc_alloc_ctx(NULL);
47 if (IS_ERR(ctx->lz4hc_comp_mem))
48 return -ENOMEM;
49
50 return 0;
51}
52
53static void lz4hc_free_ctx(struct crypto_scomp *tfm, void *ctx)
54{
55 vfree(ctx);
56}
57
58static void lz4hc_exit(struct crypto_tfm *tfm)
59{
60 struct lz4hc_ctx *ctx = crypto_tfm_ctx(tfm);
61
62 lz4hc_free_ctx(NULL, ctx->lz4hc_comp_mem);
63}
64
65static int __lz4hc_compress_crypto(const u8 *src, unsigned int slen,
66 u8 *dst, unsigned int *dlen, void *ctx)
67{
68 int out_len = LZ4_compress_HC(src, dst, slen,
69 *dlen, LZ4HC_DEFAULT_CLEVEL, ctx);
70
71 if (!out_len)
72 return -EINVAL;
73
74 *dlen = out_len;
75 return 0;
76}
77
78static int lz4hc_scompress(struct crypto_scomp *tfm, const u8 *src,
79 unsigned int slen, u8 *dst, unsigned int *dlen,
80 void *ctx)
81{
82 return __lz4hc_compress_crypto(src, slen, dst, dlen, ctx);
83}
84
85static int lz4hc_compress_crypto(struct crypto_tfm *tfm, const u8 *src,
86 unsigned int slen, u8 *dst,
87 unsigned int *dlen)
88{
89 struct lz4hc_ctx *ctx = crypto_tfm_ctx(tfm);
90
91 return __lz4hc_compress_crypto(src, slen, dst, dlen,
92 ctx->lz4hc_comp_mem);
93}
94
95static int __lz4hc_decompress_crypto(const u8 *src, unsigned int slen,
96 u8 *dst, unsigned int *dlen, void *ctx)
97{
98 int out_len = LZ4_decompress_safe(src, dst, slen, *dlen);
99
100 if (out_len < 0)
101 return -EINVAL;
102
103 *dlen = out_len;
104 return 0;
105}
106
107static int lz4hc_sdecompress(struct crypto_scomp *tfm, const u8 *src,
108 unsigned int slen, u8 *dst, unsigned int *dlen,
109 void *ctx)
110{
111 return __lz4hc_decompress_crypto(src, slen, dst, dlen, NULL);
112}
113
114static int lz4hc_decompress_crypto(struct crypto_tfm *tfm, const u8 *src,
115 unsigned int slen, u8 *dst,
116 unsigned int *dlen)
117{
118 return __lz4hc_decompress_crypto(src, slen, dst, dlen, NULL);
119}
120
121static struct crypto_alg alg_lz4hc = {
122 .cra_name = "lz4hc",
123 .cra_flags = CRYPTO_ALG_TYPE_COMPRESS,
124 .cra_ctxsize = sizeof(struct lz4hc_ctx),
125 .cra_module = THIS_MODULE,
126 .cra_init = lz4hc_init,
127 .cra_exit = lz4hc_exit,
128 .cra_u = { .compress = {
129 .coa_compress = lz4hc_compress_crypto,
130 .coa_decompress = lz4hc_decompress_crypto } }
131};
132
133static struct scomp_alg scomp = {
134 .alloc_ctx = lz4hc_alloc_ctx,
135 .free_ctx = lz4hc_free_ctx,
136 .compress = lz4hc_scompress,
137 .decompress = lz4hc_sdecompress,
138 .base = {
139 .cra_name = "lz4hc",
140 .cra_driver_name = "lz4hc-scomp",
141 .cra_module = THIS_MODULE,
142 }
143};
144
145static int __init lz4hc_mod_init(void)
146{
147 int ret;
148
149 ret = crypto_register_alg(&alg_lz4hc);
150 if (ret)
151 return ret;
152
153 ret = crypto_register_scomp(&scomp);
154 if (ret) {
155 crypto_unregister_alg(&alg_lz4hc);
156 return ret;
157 }
158
159 return ret;
160}
161
162static void __exit lz4hc_mod_fini(void)
163{
164 crypto_unregister_alg(&alg_lz4hc);
165 crypto_unregister_scomp(&scomp);
166}
167
168module_init(lz4hc_mod_init);
169module_exit(lz4hc_mod_fini);
170
171MODULE_LICENSE("GPL");
172MODULE_DESCRIPTION("LZ4HC Compression Algorithm");
173MODULE_ALIAS_CRYPTO("lz4hc");
174