1 /* 2 * Cryptographic API. 3 * 4 * This program is free software; you can redistribute it and/or modify it 5 * under the terms of the GNU General Public License version 2 as published by 6 * the Free Software Foundation. 7 * 8 * This program is distributed in the hope that it will be useful, but WITHOUT 9 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 10 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for 11 * more details. 12 * 13 * You should have received a copy of the GNU General Public License along with 14 * this program; if not, write to the Free Software Foundation, Inc., 51 15 * Franklin St, Fifth Floor, Boston, MA 02110-1301 USA 16 * 17 */ 18 19 #include <linux/init.h> 20 #include <linux/module.h> 21 #include <linux/crypto.h> 22 #include <linux/vmalloc.h> 23 #include <linux/mm.h> 24 #include <linux/lzo.h> 25 #include <crypto/internal/scompress.h> 26 27 struct lzo_ctx { 28 void *lzo_comp_mem; 29 }; 30 31 static void *lzo_alloc_ctx(struct crypto_scomp *tfm) 32 { 33 void *ctx; 34 35 ctx = kvmalloc(LZO1X_MEM_COMPRESS, GFP_KERNEL); 36 if (!ctx) 37 return ERR_PTR(-ENOMEM); 38 39 return ctx; 40 } 41 42 static int lzo_init(struct crypto_tfm *tfm) 43 { 44 struct lzo_ctx *ctx = crypto_tfm_ctx(tfm); 45 46 ctx->lzo_comp_mem = lzo_alloc_ctx(NULL); 47 if (IS_ERR(ctx->lzo_comp_mem)) 48 return -ENOMEM; 49 50 return 0; 51 } 52 53 static void lzo_free_ctx(struct crypto_scomp *tfm, void *ctx) 54 { 55 kvfree(ctx); 56 } 57 58 static void lzo_exit(struct crypto_tfm *tfm) 59 { 60 struct lzo_ctx *ctx = crypto_tfm_ctx(tfm); 61 62 lzo_free_ctx(NULL, ctx->lzo_comp_mem); 63 } 64 65 static int __lzo_compress(const u8 *src, unsigned int slen, 66 u8 *dst, unsigned int *dlen, void *ctx) 67 { 68 size_t tmp_len = *dlen; /* size_t(ulong) <-> uint on 64 bit */ 69 int err; 70 71 err = lzo1x_1_compress(src, slen, dst, &tmp_len, ctx); 72 73 if (err != LZO_E_OK) 74 return -EINVAL; 75 76 *dlen = tmp_len; 77 return 0; 78 } 79 80 static int lzo_compress(struct crypto_tfm *tfm, const u8 *src, 81 unsigned int slen, u8 *dst, unsigned int *dlen) 82 { 83 struct lzo_ctx *ctx = crypto_tfm_ctx(tfm); 84 85 return __lzo_compress(src, slen, dst, dlen, ctx->lzo_comp_mem); 86 } 87 88 static int lzo_scompress(struct crypto_scomp *tfm, const u8 *src, 89 unsigned int slen, u8 *dst, unsigned int *dlen, 90 void *ctx) 91 { 92 return __lzo_compress(src, slen, dst, dlen, ctx); 93 } 94 95 static int __lzo_decompress(const u8 *src, unsigned int slen, 96 u8 *dst, unsigned int *dlen) 97 { 98 int err; 99 size_t tmp_len = *dlen; /* size_t(ulong) <-> uint on 64 bit */ 100 101 err = lzo1x_decompress_safe(src, slen, dst, &tmp_len); 102 103 if (err != LZO_E_OK) 104 return -EINVAL; 105 106 *dlen = tmp_len; 107 return 0; 108 } 109 110 static int lzo_decompress(struct crypto_tfm *tfm, const u8 *src, 111 unsigned int slen, u8 *dst, unsigned int *dlen) 112 { 113 return __lzo_decompress(src, slen, dst, dlen); 114 } 115 116 static int lzo_sdecompress(struct crypto_scomp *tfm, const u8 *src, 117 unsigned int slen, u8 *dst, unsigned int *dlen, 118 void *ctx) 119 { 120 return __lzo_decompress(src, slen, dst, dlen); 121 } 122 123 static struct crypto_alg alg = { 124 .cra_name = "lzo", 125 .cra_flags = CRYPTO_ALG_TYPE_COMPRESS, 126 .cra_ctxsize = sizeof(struct lzo_ctx), 127 .cra_module = THIS_MODULE, 128 .cra_init = lzo_init, 129 .cra_exit = lzo_exit, 130 .cra_u = { .compress = { 131 .coa_compress = lzo_compress, 132 .coa_decompress = lzo_decompress } } 133 }; 134 135 static struct scomp_alg scomp = { 136 .alloc_ctx = lzo_alloc_ctx, 137 .free_ctx = lzo_free_ctx, 138 .compress = lzo_scompress, 139 .decompress = lzo_sdecompress, 140 .base = { 141 .cra_name = "lzo", 142 .cra_driver_name = "lzo-scomp", 143 .cra_module = THIS_MODULE, 144 } 145 }; 146 147 static int __init lzo_mod_init(void) 148 { 149 int ret; 150 151 ret = crypto_register_alg(&alg); 152 if (ret) 153 return ret; 154 155 ret = crypto_register_scomp(&scomp); 156 if (ret) { 157 crypto_unregister_alg(&alg); 158 return ret; 159 } 160 161 return ret; 162 } 163 164 static void __exit lzo_mod_fini(void) 165 { 166 crypto_unregister_alg(&alg); 167 crypto_unregister_scomp(&scomp); 168 } 169 170 subsys_initcall(lzo_mod_init); 171 module_exit(lzo_mod_fini); 172 173 MODULE_LICENSE("GPL"); 174 MODULE_DESCRIPTION("LZO Compression Algorithm"); 175 MODULE_ALIAS_CRYPTO("lzo"); 176