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
15struct lz4_ctx {
16	void *lz4_comp_mem;
17};
18
19static 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
30static 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
41static void lz4_free_ctx(struct crypto_scomp *tfm, void *ctx)
42{
43	vfree(ctx);
44}
45
46static 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
53static 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
66static 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
73static 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
81static 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
93static 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
100static 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
107static 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
120static 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
132static 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
149static void __exit lz4_mod_fini(void)
150{
151	crypto_unregister_alg(&alg_lz4);
152	crypto_unregister_scomp(&scomp);
153}
154
155subsys_initcall(lz4_mod_init);
156module_exit(lz4_mod_fini);
157
158MODULE_LICENSE("GPL");
159MODULE_DESCRIPTION("LZ4 Compression Algorithm");
160MODULE_ALIAS_CRYPTO("lz4");
161