lz4.c

 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
15static void *lz4_alloc_ctx(void)
16{
17	void *ctx;
18
19	ctx = vmalloc(LZ4_MEM_COMPRESS);
20	if (!ctx)
21		return ERR_PTR(-ENOMEM);
22
23	return ctx;
24}
25
26static void lz4_free_ctx(void *ctx)
27{
28	vfree(ctx);
29}
30
31static int __lz4_compress_crypto(const u8 *src, unsigned int slen,
32				 u8 *dst, unsigned int *dlen, void *ctx)
33{
34	int out_len = LZ4_compress_default(src, dst,
35		slen, *dlen, ctx);
36
37	if (!out_len)
38		return -EINVAL;
39
40	*dlen = out_len;
41	return 0;
42}
43
44static int lz4_scompress(struct crypto_scomp *tfm, const u8 *src,
45			 unsigned int slen, u8 *dst, unsigned int *dlen,
46			 void *ctx)
47{
48	return __lz4_compress_crypto(src, slen, dst, dlen, ctx);
49}
50
51static int __lz4_decompress_crypto(const u8 *src, unsigned int slen,
52				   u8 *dst, unsigned int *dlen, void *ctx)
53{
54	int out_len = LZ4_decompress_safe(src, dst, slen, *dlen);
55
56	if (out_len < 0)
57		return -EINVAL;
58
59	*dlen = out_len;
60	return 0;
61}
62
63static int lz4_sdecompress(struct crypto_scomp *tfm, const u8 *src,
64			   unsigned int slen, u8 *dst, unsigned int *dlen,
65			   void *ctx)
66{
67	return __lz4_decompress_crypto(src, slen, dst, dlen, NULL);
68}
69
70static struct scomp_alg scomp = {
71	.streams		= {
72		.alloc_ctx	= lz4_alloc_ctx,
73		.free_ctx	= lz4_free_ctx,
74	},
75	.compress		= lz4_scompress,
76	.decompress		= lz4_sdecompress,
77	.base			= {
78		.cra_name	= "lz4",
79		.cra_driver_name = "lz4-scomp",
80		.cra_module	 = THIS_MODULE,
81	}
82};
83
84static int __init lz4_mod_init(void)
85{
86	return crypto_register_scomp(&scomp);
87}
88
89static void __exit lz4_mod_fini(void)
90{
91	crypto_unregister_scomp(&scomp);
92}
93
94module_init(lz4_mod_init);
95module_exit(lz4_mod_fini);
96
97MODULE_LICENSE("GPL");
98MODULE_DESCRIPTION("LZ4 Compression Algorithm");
99MODULE_ALIAS_CRYPTO("lz4");