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 size_t tmp_len = *dlen; 69 int err; 70 71 err = lz4hc_compress(src, slen, dst, &tmp_len, ctx); 72 73 if (err < 0) 74 return -EINVAL; 75 76 *dlen = tmp_len; 77 return 0; 78 } 79 80 static int lz4hc_scompress(struct crypto_scomp *tfm, const u8 *src, 81 unsigned int slen, u8 *dst, unsigned int *dlen, 82 void *ctx) 83 { 84 return __lz4hc_compress_crypto(src, slen, dst, dlen, ctx); 85 } 86 87 static int lz4hc_compress_crypto(struct crypto_tfm *tfm, const u8 *src, 88 unsigned int slen, u8 *dst, 89 unsigned int *dlen) 90 { 91 struct lz4hc_ctx *ctx = crypto_tfm_ctx(tfm); 92 93 return __lz4hc_compress_crypto(src, slen, dst, dlen, 94 ctx->lz4hc_comp_mem); 95 } 96 97 static int __lz4hc_decompress_crypto(const u8 *src, unsigned int slen, 98 u8 *dst, unsigned int *dlen, void *ctx) 99 { 100 int err; 101 size_t tmp_len = *dlen; 102 size_t __slen = slen; 103 104 err = lz4_decompress_unknownoutputsize(src, __slen, dst, &tmp_len); 105 if (err < 0) 106 return -EINVAL; 107 108 *dlen = tmp_len; 109 return err; 110 } 111 112 static int lz4hc_sdecompress(struct crypto_scomp *tfm, const u8 *src, 113 unsigned int slen, u8 *dst, unsigned int *dlen, 114 void *ctx) 115 { 116 return __lz4hc_decompress_crypto(src, slen, dst, dlen, NULL); 117 } 118 119 static int lz4hc_decompress_crypto(struct crypto_tfm *tfm, const u8 *src, 120 unsigned int slen, u8 *dst, 121 unsigned int *dlen) 122 { 123 return __lz4hc_decompress_crypto(src, slen, dst, dlen, NULL); 124 } 125 126 static struct crypto_alg alg_lz4hc = { 127 .cra_name = "lz4hc", 128 .cra_flags = CRYPTO_ALG_TYPE_COMPRESS, 129 .cra_ctxsize = sizeof(struct lz4hc_ctx), 130 .cra_module = THIS_MODULE, 131 .cra_list = LIST_HEAD_INIT(alg_lz4hc.cra_list), 132 .cra_init = lz4hc_init, 133 .cra_exit = lz4hc_exit, 134 .cra_u = { .compress = { 135 .coa_compress = lz4hc_compress_crypto, 136 .coa_decompress = lz4hc_decompress_crypto } } 137 }; 138 139 static struct scomp_alg scomp = { 140 .alloc_ctx = lz4hc_alloc_ctx, 141 .free_ctx = lz4hc_free_ctx, 142 .compress = lz4hc_scompress, 143 .decompress = lz4hc_sdecompress, 144 .base = { 145 .cra_name = "lz4hc", 146 .cra_driver_name = "lz4hc-scomp", 147 .cra_module = THIS_MODULE, 148 } 149 }; 150 151 static int __init lz4hc_mod_init(void) 152 { 153 int ret; 154 155 ret = crypto_register_alg(&alg_lz4hc); 156 if (ret) 157 return ret; 158 159 ret = crypto_register_scomp(&scomp); 160 if (ret) { 161 crypto_unregister_alg(&alg_lz4hc); 162 return ret; 163 } 164 165 return ret; 166 } 167 168 static void __exit lz4hc_mod_fini(void) 169 { 170 crypto_unregister_alg(&alg_lz4hc); 171 crypto_unregister_scomp(&scomp); 172 } 173 174 module_init(lz4hc_mod_init); 175 module_exit(lz4hc_mod_fini); 176 177 MODULE_LICENSE("GPL"); 178 MODULE_DESCRIPTION("LZ4HC Compression Algorithm"); 179 MODULE_ALIAS_CRYPTO("lz4hc"); 180