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 27 struct lz4_ctx { 28 void *lz4_comp_mem; 29 }; 30 31 static int lz4_init(struct crypto_tfm *tfm) 32 { 33 struct lz4_ctx *ctx = crypto_tfm_ctx(tfm); 34 35 ctx->lz4_comp_mem = vmalloc(LZ4_MEM_COMPRESS); 36 if (!ctx->lz4_comp_mem) 37 return -ENOMEM; 38 39 return 0; 40 } 41 42 static void lz4_exit(struct crypto_tfm *tfm) 43 { 44 struct lz4_ctx *ctx = crypto_tfm_ctx(tfm); 45 vfree(ctx->lz4_comp_mem); 46 } 47 48 static int lz4_compress_crypto(struct crypto_tfm *tfm, const u8 *src, 49 unsigned int slen, u8 *dst, unsigned int *dlen) 50 { 51 struct lz4_ctx *ctx = crypto_tfm_ctx(tfm); 52 size_t tmp_len = *dlen; 53 int err; 54 55 err = lz4_compress(src, slen, dst, &tmp_len, ctx->lz4_comp_mem); 56 57 if (err < 0) 58 return -EINVAL; 59 60 *dlen = tmp_len; 61 return 0; 62 } 63 64 static int lz4_decompress_crypto(struct crypto_tfm *tfm, const u8 *src, 65 unsigned int slen, u8 *dst, unsigned int *dlen) 66 { 67 int err; 68 size_t tmp_len = *dlen; 69 size_t __slen = slen; 70 71 err = lz4_decompress(src, &__slen, dst, tmp_len); 72 if (err < 0) 73 return -EINVAL; 74 75 *dlen = tmp_len; 76 return err; 77 } 78 79 static struct crypto_alg alg_lz4 = { 80 .cra_name = "lz4", 81 .cra_flags = CRYPTO_ALG_TYPE_COMPRESS, 82 .cra_ctxsize = sizeof(struct lz4_ctx), 83 .cra_module = THIS_MODULE, 84 .cra_list = LIST_HEAD_INIT(alg_lz4.cra_list), 85 .cra_init = lz4_init, 86 .cra_exit = lz4_exit, 87 .cra_u = { .compress = { 88 .coa_compress = lz4_compress_crypto, 89 .coa_decompress = lz4_decompress_crypto } } 90 }; 91 92 static int __init lz4_mod_init(void) 93 { 94 return crypto_register_alg(&alg_lz4); 95 } 96 97 static void __exit lz4_mod_fini(void) 98 { 99 crypto_unregister_alg(&alg_lz4); 100 } 101 102 module_init(lz4_mod_init); 103 module_exit(lz4_mod_fini); 104 105 MODULE_LICENSE("GPL"); 106 MODULE_DESCRIPTION("LZ4 Compression Algorithm"); 107