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 size_t tmp_len = *dlen; 70 int err; 71 72 err = lz4_compress(src, slen, dst, &tmp_len, ctx); 73 74 if (err < 0) 75 return -EINVAL; 76 77 *dlen = tmp_len; 78 return 0; 79 } 80 81 static int lz4_scompress(struct crypto_scomp *tfm, const u8 *src, 82 unsigned int slen, u8 *dst, unsigned int *dlen, 83 void *ctx) 84 { 85 return __lz4_compress_crypto(src, slen, dst, dlen, ctx); 86 } 87 88 static int lz4_compress_crypto(struct crypto_tfm *tfm, const u8 *src, 89 unsigned int slen, u8 *dst, unsigned int *dlen) 90 { 91 struct lz4_ctx *ctx = crypto_tfm_ctx(tfm); 92 93 return __lz4_compress_crypto(src, slen, dst, dlen, ctx->lz4_comp_mem); 94 } 95 96 static int __lz4_decompress_crypto(const u8 *src, unsigned int slen, 97 u8 *dst, unsigned int *dlen, void *ctx) 98 { 99 int err; 100 size_t tmp_len = *dlen; 101 size_t __slen = slen; 102 103 err = lz4_decompress_unknownoutputsize(src, __slen, dst, &tmp_len); 104 if (err < 0) 105 return -EINVAL; 106 107 *dlen = tmp_len; 108 return err; 109 } 110 111 static int lz4_sdecompress(struct crypto_scomp *tfm, const u8 *src, 112 unsigned int slen, u8 *dst, unsigned int *dlen, 113 void *ctx) 114 { 115 return __lz4_decompress_crypto(src, slen, dst, dlen, NULL); 116 } 117 118 static int lz4_decompress_crypto(struct crypto_tfm *tfm, const u8 *src, 119 unsigned int slen, u8 *dst, 120 unsigned int *dlen) 121 { 122 return __lz4_decompress_crypto(src, slen, dst, dlen, NULL); 123 } 124 125 static struct crypto_alg alg_lz4 = { 126 .cra_name = "lz4", 127 .cra_flags = CRYPTO_ALG_TYPE_COMPRESS, 128 .cra_ctxsize = sizeof(struct lz4_ctx), 129 .cra_module = THIS_MODULE, 130 .cra_list = LIST_HEAD_INIT(alg_lz4.cra_list), 131 .cra_init = lz4_init, 132 .cra_exit = lz4_exit, 133 .cra_u = { .compress = { 134 .coa_compress = lz4_compress_crypto, 135 .coa_decompress = lz4_decompress_crypto } } 136 }; 137 138 static struct scomp_alg scomp = { 139 .alloc_ctx = lz4_alloc_ctx, 140 .free_ctx = lz4_free_ctx, 141 .compress = lz4_scompress, 142 .decompress = lz4_sdecompress, 143 .base = { 144 .cra_name = "lz4", 145 .cra_driver_name = "lz4-scomp", 146 .cra_module = THIS_MODULE, 147 } 148 }; 149 150 static int __init lz4_mod_init(void) 151 { 152 int ret; 153 154 ret = crypto_register_alg(&alg_lz4); 155 if (ret) 156 return ret; 157 158 ret = crypto_register_scomp(&scomp); 159 if (ret) { 160 crypto_unregister_alg(&alg_lz4); 161 return ret; 162 } 163 164 return ret; 165 } 166 167 static void __exit lz4_mod_fini(void) 168 { 169 crypto_unregister_alg(&alg_lz4); 170 crypto_unregister_scomp(&scomp); 171 } 172 173 module_init(lz4_mod_init); 174 module_exit(lz4_mod_fini); 175 176 MODULE_LICENSE("GPL"); 177 MODULE_DESCRIPTION("LZ4 Compression Algorithm"); 178 MODULE_ALIAS_CRYPTO("lz4"); 179