| 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 | |
| 27 | static zstd_parameters zstd_params(void) |
| 28 | { |
| 29 | return zstd_get_params(ZSTD_DEF_LEVEL, estimated_src_size: 0); |
| 30 | } |
| 31 | |
| 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(parameters: ¶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(workspace: ctx->cwksp, workspace_size: wksp_size); |
| 45 | if (!ctx->cctx) { |
| 46 | ret = -EINVAL; |
| 47 | goto out_free; |
| 48 | } |
| 49 | out: |
| 50 | return ret; |
| 51 | out_free: |
| 52 | vfree(addr: ctx->cwksp); |
| 53 | goto out; |
| 54 | } |
| 55 | |
| 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(workspace: ctx->dwksp, workspace_size: wksp_size); |
| 68 | if (!ctx->dctx) { |
| 69 | ret = -EINVAL; |
| 70 | goto out_free; |
| 71 | } |
| 72 | out: |
| 73 | return ret; |
| 74 | out_free: |
| 75 | vfree(addr: ctx->dwksp); |
| 76 | goto out; |
| 77 | } |
| 78 | |
| 79 | static void zstd_comp_exit(struct zstd_ctx *ctx) |
| 80 | { |
| 81 | vfree(addr: ctx->cwksp); |
| 82 | ctx->cwksp = NULL; |
| 83 | ctx->cctx = NULL; |
| 84 | } |
| 85 | |
| 86 | static void zstd_decomp_exit(struct zstd_ctx *ctx) |
| 87 | { |
| 88 | vfree(addr: ctx->dwksp); |
| 89 | ctx->dwksp = NULL; |
| 90 | ctx->dctx = NULL; |
| 91 | } |
| 92 | |
| 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 | |
| 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(error: -ENOMEM); |
| 114 | |
| 115 | ret = __zstd_init(ctx); |
| 116 | if (ret) { |
| 117 | kfree(objp: ctx); |
| 118 | return ERR_PTR(error: ret); |
| 119 | } |
| 120 | |
| 121 | return ctx; |
| 122 | } |
| 123 | |
| 124 | static void __zstd_exit(void *ctx) |
| 125 | { |
| 126 | zstd_comp_exit(ctx); |
| 127 | zstd_decomp_exit(ctx); |
| 128 | } |
| 129 | |
| 130 | static void zstd_free_ctx(void *ctx) |
| 131 | { |
| 132 | __zstd_exit(ctx); |
| 133 | kfree_sensitive(objp: ctx); |
| 134 | } |
| 135 | |
| 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(cctx: zctx->cctx, dst, dst_capacity: *dlen, src, src_size: slen, parameters: ¶ms); |
| 144 | if (zstd_is_error(code: out_len)) |
| 145 | return -EINVAL; |
| 146 | *dlen = out_len; |
| 147 | return 0; |
| 148 | } |
| 149 | |
| 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 | |
| 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(dctx: zctx->dctx, dst, dst_capacity: *dlen, src, src_size: slen); |
| 164 | if (zstd_is_error(code: out_len)) |
| 165 | return -EINVAL; |
| 166 | *dlen = out_len; |
| 167 | return 0; |
| 168 | } |
| 169 | |
| 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 | |
| 189 | static int __init zstd_mod_init(void) |
| 190 | { |
| 191 | return crypto_register_scomp(alg: &scomp); |
| 192 | } |
| 193 | |
| 194 | static void __exit zstd_mod_fini(void) |
| 195 | { |
| 196 | crypto_unregister_scomp(alg: &scomp); |
| 197 | } |
| 198 | |
| 199 | module_init(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 | |