1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * Cryptographic API.
4 *
5 * Copyright (c) 2017-present, Facebook, Inc.
6 */
7 #include <linux/crypto.h>
8 #include <linux/init.h>
9 #include <linux/interrupt.h>
10 #include <linux/mm.h>
11 #include <linux/module.h>
12 #include <linux/net.h>
13 #include <linux/vmalloc.h>
14 #include <linux/zstd.h>
15 #include <crypto/internal/scompress.h>
16
17
18 #define ZSTD_DEF_LEVEL 3
19
20 struct zstd_ctx {
21 zstd_cctx *cctx;
22 zstd_dctx *dctx;
23 void *cwksp;
24 void *dwksp;
25 };
26
zstd_params(void)27 static zstd_parameters zstd_params(void)
28 {
29 return zstd_get_params(ZSTD_DEF_LEVEL, 0);
30 }
31
zstd_comp_init(struct zstd_ctx * ctx)32 static int zstd_comp_init(struct zstd_ctx *ctx)
33 {
34 int ret = 0;
35 const zstd_parameters params = zstd_params();
36 const size_t wksp_size = zstd_cctx_workspace_bound(¶ms.cParams);
37
38 ctx->cwksp = vzalloc(wksp_size);
39 if (!ctx->cwksp) {
40 ret = -ENOMEM;
41 goto out;
42 }
43
44 ctx->cctx = zstd_init_cctx(ctx->cwksp, wksp_size);
45 if (!ctx->cctx) {
46 ret = -EINVAL;
47 goto out_free;
48 }
49 out:
50 return ret;
51 out_free:
52 vfree(ctx->cwksp);
53 goto out;
54 }
55
zstd_decomp_init(struct zstd_ctx * ctx)56 static int zstd_decomp_init(struct zstd_ctx *ctx)
57 {
58 int ret = 0;
59 const size_t wksp_size = zstd_dctx_workspace_bound();
60
61 ctx->dwksp = vzalloc(wksp_size);
62 if (!ctx->dwksp) {
63 ret = -ENOMEM;
64 goto out;
65 }
66
67 ctx->dctx = zstd_init_dctx(ctx->dwksp, wksp_size);
68 if (!ctx->dctx) {
69 ret = -EINVAL;
70 goto out_free;
71 }
72 out:
73 return ret;
74 out_free:
75 vfree(ctx->dwksp);
76 goto out;
77 }
78
zstd_comp_exit(struct zstd_ctx * ctx)79 static void zstd_comp_exit(struct zstd_ctx *ctx)
80 {
81 vfree(ctx->cwksp);
82 ctx->cwksp = NULL;
83 ctx->cctx = NULL;
84 }
85
zstd_decomp_exit(struct zstd_ctx * ctx)86 static void zstd_decomp_exit(struct zstd_ctx *ctx)
87 {
88 vfree(ctx->dwksp);
89 ctx->dwksp = NULL;
90 ctx->dctx = NULL;
91 }
92
__zstd_init(void * ctx)93 static int __zstd_init(void *ctx)
94 {
95 int ret;
96
97 ret = zstd_comp_init(ctx);
98 if (ret)
99 return ret;
100 ret = zstd_decomp_init(ctx);
101 if (ret)
102 zstd_comp_exit(ctx);
103 return ret;
104 }
105
zstd_alloc_ctx(void)106 static void *zstd_alloc_ctx(void)
107 {
108 int ret;
109 struct zstd_ctx *ctx;
110
111 ctx = kzalloc(sizeof(*ctx), GFP_KERNEL);
112 if (!ctx)
113 return ERR_PTR(-ENOMEM);
114
115 ret = __zstd_init(ctx);
116 if (ret) {
117 kfree(ctx);
118 return ERR_PTR(ret);
119 }
120
121 return ctx;
122 }
123
__zstd_exit(void * ctx)124 static void __zstd_exit(void *ctx)
125 {
126 zstd_comp_exit(ctx);
127 zstd_decomp_exit(ctx);
128 }
129
zstd_free_ctx(void * ctx)130 static void zstd_free_ctx(void *ctx)
131 {
132 __zstd_exit(ctx);
133 kfree_sensitive(ctx);
134 }
135
__zstd_compress(const u8 * src,unsigned int slen,u8 * dst,unsigned int * dlen,void * ctx)136 static int __zstd_compress(const u8 *src, unsigned int slen,
137 u8 *dst, unsigned int *dlen, void *ctx)
138 {
139 size_t out_len;
140 struct zstd_ctx *zctx = ctx;
141 const zstd_parameters params = zstd_params();
142
143 out_len = zstd_compress_cctx(zctx->cctx, dst, *dlen, src, slen, ¶ms);
144 if (zstd_is_error(out_len))
145 return -EINVAL;
146 *dlen = out_len;
147 return 0;
148 }
149
zstd_scompress(struct crypto_scomp * tfm,const u8 * src,unsigned int slen,u8 * dst,unsigned int * dlen,void * ctx)150 static int zstd_scompress(struct crypto_scomp *tfm, const u8 *src,
151 unsigned int slen, u8 *dst, unsigned int *dlen,
152 void *ctx)
153 {
154 return __zstd_compress(src, slen, dst, dlen, ctx);
155 }
156
__zstd_decompress(const u8 * src,unsigned int slen,u8 * dst,unsigned int * dlen,void * ctx)157 static int __zstd_decompress(const u8 *src, unsigned int slen,
158 u8 *dst, unsigned int *dlen, void *ctx)
159 {
160 size_t out_len;
161 struct zstd_ctx *zctx = ctx;
162
163 out_len = zstd_decompress_dctx(zctx->dctx, dst, *dlen, src, slen);
164 if (zstd_is_error(out_len))
165 return -EINVAL;
166 *dlen = out_len;
167 return 0;
168 }
169
zstd_sdecompress(struct crypto_scomp * tfm,const u8 * src,unsigned int slen,u8 * dst,unsigned int * dlen,void * ctx)170 static int zstd_sdecompress(struct crypto_scomp *tfm, const u8 *src,
171 unsigned int slen, u8 *dst, unsigned int *dlen,
172 void *ctx)
173 {
174 return __zstd_decompress(src, slen, dst, dlen, ctx);
175 }
176
177 static struct scomp_alg scomp = {
178 .alloc_ctx = zstd_alloc_ctx,
179 .free_ctx = zstd_free_ctx,
180 .compress = zstd_scompress,
181 .decompress = zstd_sdecompress,
182 .base = {
183 .cra_name = "zstd",
184 .cra_driver_name = "zstd-scomp",
185 .cra_module = THIS_MODULE,
186 }
187 };
188
zstd_mod_init(void)189 static int __init zstd_mod_init(void)
190 {
191 return crypto_register_scomp(&scomp);
192 }
193
zstd_mod_fini(void)194 static void __exit zstd_mod_fini(void)
195 {
196 crypto_unregister_scomp(&scomp);
197 }
198
199 subsys_initcall(zstd_mod_init);
200 module_exit(zstd_mod_fini);
201
202 MODULE_LICENSE("GPL");
203 MODULE_DESCRIPTION("Zstd Compression Algorithm");
204 MODULE_ALIAS_CRYPTO("zstd");
205