1 /* 2 * Cryptographic API. 3 * 4 * Copyright (c) 2013 Chanho Min <chanho.min@lge.com> 5 * 6 * This program is free software; you can redistribute it and/or modify it 7 * under the terms of the GNU General Public License version 2 as published by 8 * the Free Software Foundation. 9 * 10 * This program is distributed in the hope that it will be useful, but WITHOUT 11 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 12 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for 13 * more details. 14 * 15 * You should have received a copy of the GNU General Public License along with 16 * this program; if not, write to the Free Software Foundation, Inc., 51 17 * Franklin St, Fifth Floor, Boston, MA 02110-1301 USA 18 * 19 */ 20 #include <linux/init.h> 21 #include <linux/module.h> 22 #include <linux/crypto.h> 23 #include <linux/vmalloc.h> 24 #include <linux/lz4.h> 25 #include <crypto/internal/scompress.h> 26 27 struct lz4hc_ctx { 28 void *lz4hc_comp_mem; 29 }; 30 31 static void *lz4hc_alloc_ctx(struct crypto_scomp *tfm) 32 { 33 void *ctx; 34 35 ctx = vmalloc(LZ4HC_MEM_COMPRESS); 36 if (!ctx) 37 return ERR_PTR(-ENOMEM); 38 39 return ctx; 40 } 41 42 static int lz4hc_init(struct crypto_tfm *tfm) 43 { 44 struct lz4hc_ctx *ctx = crypto_tfm_ctx(tfm); 45 46 ctx->lz4hc_comp_mem = lz4hc_alloc_ctx(NULL); 47 if (IS_ERR(ctx->lz4hc_comp_mem)) 48 return -ENOMEM; 49 50 return 0; 51 } 52 53 static void lz4hc_free_ctx(struct crypto_scomp *tfm, void *ctx) 54 { 55 vfree(ctx); 56 } 57 58 static void lz4hc_exit(struct crypto_tfm *tfm) 59 { 60 struct lz4hc_ctx *ctx = crypto_tfm_ctx(tfm); 61 62 lz4hc_free_ctx(NULL, ctx->lz4hc_comp_mem); 63 } 64 65 static int __lz4hc_compress_crypto(const u8 *src, unsigned int slen, 66 u8 *dst, unsigned int *dlen, void *ctx) 67 { 68 int out_len = LZ4_compress_HC(src, dst, slen, 69 *dlen, LZ4HC_DEFAULT_CLEVEL, ctx); 70 71 if (!out_len) 72 return -EINVAL; 73 74 *dlen = out_len; 75 return 0; 76 } 77 78 static int lz4hc_scompress(struct crypto_scomp *tfm, const u8 *src, 79 unsigned int slen, u8 *dst, unsigned int *dlen, 80 void *ctx) 81 { 82 return __lz4hc_compress_crypto(src, slen, dst, dlen, ctx); 83 } 84 85 static int lz4hc_compress_crypto(struct crypto_tfm *tfm, const u8 *src, 86 unsigned int slen, u8 *dst, 87 unsigned int *dlen) 88 { 89 struct lz4hc_ctx *ctx = crypto_tfm_ctx(tfm); 90 91 return __lz4hc_compress_crypto(src, slen, dst, dlen, 92 ctx->lz4hc_comp_mem); 93 } 94 95 static int __lz4hc_decompress_crypto(const u8 *src, unsigned int slen, 96 u8 *dst, unsigned int *dlen, void *ctx) 97 { 98 int out_len = LZ4_decompress_safe(src, dst, slen, *dlen); 99 100 if (out_len < 0) 101 return -EINVAL; 102 103 *dlen = out_len; 104 return 0; 105 } 106 107 static int lz4hc_sdecompress(struct crypto_scomp *tfm, const u8 *src, 108 unsigned int slen, u8 *dst, unsigned int *dlen, 109 void *ctx) 110 { 111 return __lz4hc_decompress_crypto(src, slen, dst, dlen, NULL); 112 } 113 114 static int lz4hc_decompress_crypto(struct crypto_tfm *tfm, const u8 *src, 115 unsigned int slen, u8 *dst, 116 unsigned int *dlen) 117 { 118 return __lz4hc_decompress_crypto(src, slen, dst, dlen, NULL); 119 } 120 121 static struct crypto_alg alg_lz4hc = { 122 .cra_name = "lz4hc", 123 .cra_flags = CRYPTO_ALG_TYPE_COMPRESS, 124 .cra_ctxsize = sizeof(struct lz4hc_ctx), 125 .cra_module = THIS_MODULE, 126 .cra_init = lz4hc_init, 127 .cra_exit = lz4hc_exit, 128 .cra_u = { .compress = { 129 .coa_compress = lz4hc_compress_crypto, 130 .coa_decompress = lz4hc_decompress_crypto } } 131 }; 132 133 static struct scomp_alg scomp = { 134 .alloc_ctx = lz4hc_alloc_ctx, 135 .free_ctx = lz4hc_free_ctx, 136 .compress = lz4hc_scompress, 137 .decompress = lz4hc_sdecompress, 138 .base = { 139 .cra_name = "lz4hc", 140 .cra_driver_name = "lz4hc-scomp", 141 .cra_module = THIS_MODULE, 142 } 143 }; 144 145 static int __init lz4hc_mod_init(void) 146 { 147 int ret; 148 149 ret = crypto_register_alg(&alg_lz4hc); 150 if (ret) 151 return ret; 152 153 ret = crypto_register_scomp(&scomp); 154 if (ret) { 155 crypto_unregister_alg(&alg_lz4hc); 156 return ret; 157 } 158 159 return ret; 160 } 161 162 static void __exit lz4hc_mod_fini(void) 163 { 164 crypto_unregister_alg(&alg_lz4hc); 165 crypto_unregister_scomp(&scomp); 166 } 167 168 subsys_initcall(lz4hc_mod_init); 169 module_exit(lz4hc_mod_fini); 170 171 MODULE_LICENSE("GPL"); 172 MODULE_DESCRIPTION("LZ4HC Compression Algorithm"); 173 MODULE_ALIAS_CRYPTO("lz4hc"); 174