1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * Cryptographic API.
4 *
5 * Copyright (c) 2013 Chanho Min <chanho.min@lge.com>
6 */
7
8 #include <linux/init.h>
9 #include <linux/module.h>
10 #include <linux/crypto.h>
11 #include <linux/vmalloc.h>
12 #include <linux/lz4.h>
13 #include <crypto/internal/scompress.h>
14
15 struct lz4_ctx {
16 void *lz4_comp_mem;
17 };
18
19 static void *lz4_alloc_ctx(struct crypto_scomp *tfm)
20 {
21 void *ctx;
22
23 ctx = vmalloc(LZ4_MEM_COMPRESS);
24 if (!ctx)
25 return ERR_PTR(-ENOMEM);
26
27 return ctx;
28 }
29
30 static int lz4_init(struct crypto_tfm *tfm)
31 {
32 struct lz4_ctx *ctx = crypto_tfm_ctx(tfm);
33
34 ctx->lz4_comp_mem = lz4_alloc_ctx(NULL);
35 if (IS_ERR(ctx->lz4_comp_mem))
36 return -ENOMEM;
37
38 return 0;
39 }
40
41 static void lz4_free_ctx(struct crypto_scomp *tfm, void *ctx)
42 {
43 vfree(ctx);
44 }
45
46 static void lz4_exit(struct crypto_tfm *tfm)
47 {
48 struct lz4_ctx *ctx = crypto_tfm_ctx(tfm);
49
50 lz4_free_ctx(NULL, ctx->lz4_comp_mem);
51 }
52
53 static int __lz4_compress_crypto(const u8 *src, unsigned int slen,
54 u8 *dst, unsigned int *dlen, void *ctx)
55 {
56 int out_len = LZ4_compress_default(src, dst,
57 slen, *dlen, ctx);
58
59 if (!out_len)
60 return -EINVAL;
61
62 *dlen = out_len;
63 return 0;
64 }
65
66 static int lz4_scompress(struct crypto_scomp *tfm, const u8 *src,
67 unsigned int slen, u8 *dst, unsigned int *dlen,
68 void *ctx)
69 {
70 return __lz4_compress_crypto(src, slen, dst, dlen, ctx);
71 }
72
73 static int lz4_compress_crypto(struct crypto_tfm *tfm, const u8 *src,
74 unsigned int slen, u8 *dst, unsigned int *dlen)
75 {
76 struct lz4_ctx *ctx = crypto_tfm_ctx(tfm);
77
78 return __lz4_compress_crypto(src, slen, dst, dlen, ctx->lz4_comp_mem);
79 }
80
81 static int __lz4_decompress_crypto(const u8 *src, unsigned int slen,
82 u8 *dst, unsigned int *dlen, void *ctx)
83 {
84 int out_len = LZ4_decompress_safe(src, dst, slen, *dlen);
85
86 if (out_len < 0)
87 return -EINVAL;
88
89 *dlen = out_len;
90 return 0;
91 }
92
93 static int lz4_sdecompress(struct crypto_scomp *tfm, const u8 *src,
94 unsigned int slen, u8 *dst, unsigned int *dlen,
95 void *ctx)
96 {
97 return __lz4_decompress_crypto(src, slen, dst, dlen, NULL);
98 }
99
100 static int lz4_decompress_crypto(struct crypto_tfm *tfm, const u8 *src,
101 unsigned int slen, u8 *dst,
102 unsigned int *dlen)
103 {
104 return __lz4_decompress_crypto(src, slen, dst, dlen, NULL);
105 }
106
107 static struct crypto_alg alg_lz4 = {
108 .cra_name = "lz4",
109 .cra_driver_name = "lz4-generic",
110 .cra_flags = CRYPTO_ALG_TYPE_COMPRESS,
111 .cra_ctxsize = sizeof(struct lz4_ctx),
112 .cra_module = THIS_MODULE,
113 .cra_init = lz4_init,
114 .cra_exit = lz4_exit,
115 .cra_u = { .compress = {
116 .coa_compress = lz4_compress_crypto,
117 .coa_decompress = lz4_decompress_crypto } }
118 };
119
120 static struct scomp_alg scomp = {
121 .alloc_ctx = lz4_alloc_ctx,
122 .free_ctx = lz4_free_ctx,
123 .compress = lz4_scompress,
124 .decompress = lz4_sdecompress,
125 .base = {
126 .cra_name = "lz4",
127 .cra_driver_name = "lz4-scomp",
128 .cra_module = THIS_MODULE,
129 }
130 };
131
132 static int __init lz4_mod_init(void)
133 {
134 int ret;
135
136 ret = crypto_register_alg(&alg_lz4);
137 if (ret)
138 return ret;
139
140 ret = crypto_register_scomp(&scomp);
141 if (ret) {
142 crypto_unregister_alg(&alg_lz4);
143 return ret;
144 }
145
146 return ret;
147 }
148
149 static void __exit lz4_mod_fini(void)
150 {
151 crypto_unregister_alg(&alg_lz4);
152 crypto_unregister_scomp(&scomp);
153 }
154
155 subsys_initcall(lz4_mod_init);
156 module_exit(lz4_mod_fini);
157
158 MODULE_LICENSE("GPL");
159 MODULE_DESCRIPTION("LZ4 Compression Algorithm");
160 MODULE_ALIAS_CRYPTO("lz4");
161
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