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 21 #include <linux/init.h> 22 #include <linux/module.h> 23 #include <linux/crypto.h> 24 #include <linux/vmalloc.h> 25 #include <linux/lz4.h> 26 #include <crypto/internal/scompress.h> 27 28 struct lz4_ctx { 29 void *lz4_comp_mem; 30 }; 31 32 static void *lz4_alloc_ctx(struct crypto_scomp *tfm) 33 { 34 void *ctx; 35 36 ctx = vmalloc(LZ4_MEM_COMPRESS); 37 if (!ctx) 38 return ERR_PTR(-ENOMEM); 39 40 return ctx; 41 } 42 43 static int lz4_init(struct crypto_tfm *tfm) 44 { 45 struct lz4_ctx *ctx = crypto_tfm_ctx(tfm); 46 47 ctx->lz4_comp_mem = lz4_alloc_ctx(NULL); 48 if (IS_ERR(ctx->lz4_comp_mem)) 49 return -ENOMEM; 50 51 return 0; 52 } 53 54 static void lz4_free_ctx(struct crypto_scomp *tfm, void *ctx) 55 { 56 vfree(ctx); 57 } 58 59 static void lz4_exit(struct crypto_tfm *tfm) 60 { 61 struct lz4_ctx *ctx = crypto_tfm_ctx(tfm); 62 63 lz4_free_ctx(NULL, ctx->lz4_comp_mem); 64 } 65 66 static int __lz4_compress_crypto(const u8 *src, unsigned int slen, 67 u8 *dst, unsigned int *dlen, void *ctx) 68 { 69 int out_len = LZ4_compress_default(src, dst, 70 slen, *dlen, ctx); 71 72 if (!out_len) 73 return -EINVAL; 74 75 *dlen = out_len; 76 return 0; 77 } 78 79 static int lz4_scompress(struct crypto_scomp *tfm, const u8 *src, 80 unsigned int slen, u8 *dst, unsigned int *dlen, 81 void *ctx) 82 { 83 return __lz4_compress_crypto(src, slen, dst, dlen, ctx); 84 } 85 86 static int lz4_compress_crypto(struct crypto_tfm *tfm, const u8 *src, 87 unsigned int slen, u8 *dst, unsigned int *dlen) 88 { 89 struct lz4_ctx *ctx = crypto_tfm_ctx(tfm); 90 91 return __lz4_compress_crypto(src, slen, dst, dlen, ctx->lz4_comp_mem); 92 } 93 94 static int __lz4_decompress_crypto(const u8 *src, unsigned int slen, 95 u8 *dst, unsigned int *dlen, void *ctx) 96 { 97 int out_len = LZ4_decompress_safe(src, dst, slen, *dlen); 98 99 if (out_len < 0) 100 return out_len; 101 102 *dlen = out_len; 103 return 0; 104 } 105 106 static int lz4_sdecompress(struct crypto_scomp *tfm, const u8 *src, 107 unsigned int slen, u8 *dst, unsigned int *dlen, 108 void *ctx) 109 { 110 return __lz4_decompress_crypto(src, slen, dst, dlen, NULL); 111 } 112 113 static int lz4_decompress_crypto(struct crypto_tfm *tfm, const u8 *src, 114 unsigned int slen, u8 *dst, 115 unsigned int *dlen) 116 { 117 return __lz4_decompress_crypto(src, slen, dst, dlen, NULL); 118 } 119 120 static struct crypto_alg alg_lz4 = { 121 .cra_name = "lz4", 122 .cra_flags = CRYPTO_ALG_TYPE_COMPRESS, 123 .cra_ctxsize = sizeof(struct lz4_ctx), 124 .cra_module = THIS_MODULE, 125 .cra_list = LIST_HEAD_INIT(alg_lz4.cra_list), 126 .cra_init = lz4_init, 127 .cra_exit = lz4_exit, 128 .cra_u = { .compress = { 129 .coa_compress = lz4_compress_crypto, 130 .coa_decompress = lz4_decompress_crypto } } 131 }; 132 133 static struct scomp_alg scomp = { 134 .alloc_ctx = lz4_alloc_ctx, 135 .free_ctx = lz4_free_ctx, 136 .compress = lz4_scompress, 137 .decompress = lz4_sdecompress, 138 .base = { 139 .cra_name = "lz4", 140 .cra_driver_name = "lz4-scomp", 141 .cra_module = THIS_MODULE, 142 } 143 }; 144 145 static int __init lz4_mod_init(void) 146 { 147 int ret; 148 149 ret = crypto_register_alg(&alg_lz4); 150 if (ret) 151 return ret; 152 153 ret = crypto_register_scomp(&scomp); 154 if (ret) { 155 crypto_unregister_alg(&alg_lz4); 156 return ret; 157 } 158 159 return ret; 160 } 161 162 static void __exit lz4_mod_fini(void) 163 { 164 crypto_unregister_alg(&alg_lz4); 165 crypto_unregister_scomp(&scomp); 166 } 167 168 module_init(lz4_mod_init); 169 module_exit(lz4_mod_fini); 170 171 MODULE_LICENSE("GPL"); 172 MODULE_DESCRIPTION("LZ4 Compression Algorithm"); 173 MODULE_ALIAS_CRYPTO("lz4"); 174