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 26 struct lzo_ctx { 27 void *lzo_comp_mem; 28 }; 29 30 static int lzo_init(struct crypto_tfm *tfm) 31 { 32 struct lzo_ctx *ctx = crypto_tfm_ctx(tfm); 33 34 ctx->lzo_comp_mem = kmalloc(LZO1X_MEM_COMPRESS, 35 GFP_KERNEL | __GFP_NOWARN); 36 if (!ctx->lzo_comp_mem) 37 ctx->lzo_comp_mem = vmalloc(LZO1X_MEM_COMPRESS); 38 if (!ctx->lzo_comp_mem) 39 return -ENOMEM; 40 41 return 0; 42 } 43 44 static void lzo_exit(struct crypto_tfm *tfm) 45 { 46 struct lzo_ctx *ctx = crypto_tfm_ctx(tfm); 47 48 kvfree(ctx->lzo_comp_mem); 49 } 50 51 static int lzo_compress(struct crypto_tfm *tfm, const u8 *src, 52 unsigned int slen, u8 *dst, unsigned int *dlen) 53 { 54 struct lzo_ctx *ctx = crypto_tfm_ctx(tfm); 55 size_t tmp_len = *dlen; /* size_t(ulong) <-> uint on 64 bit */ 56 int err; 57 58 err = lzo1x_1_compress(src, slen, dst, &tmp_len, ctx->lzo_comp_mem); 59 60 if (err != LZO_E_OK) 61 return -EINVAL; 62 63 *dlen = tmp_len; 64 return 0; 65 } 66 67 static int lzo_decompress(struct crypto_tfm *tfm, const u8 *src, 68 unsigned int slen, u8 *dst, unsigned int *dlen) 69 { 70 int err; 71 size_t tmp_len = *dlen; /* size_t(ulong) <-> uint on 64 bit */ 72 73 err = lzo1x_decompress_safe(src, slen, dst, &tmp_len); 74 75 if (err != LZO_E_OK) 76 return -EINVAL; 77 78 *dlen = tmp_len; 79 return 0; 80 81 } 82 83 static struct crypto_alg alg = { 84 .cra_name = "lzo", 85 .cra_flags = CRYPTO_ALG_TYPE_COMPRESS, 86 .cra_ctxsize = sizeof(struct lzo_ctx), 87 .cra_module = THIS_MODULE, 88 .cra_init = lzo_init, 89 .cra_exit = lzo_exit, 90 .cra_u = { .compress = { 91 .coa_compress = lzo_compress, 92 .coa_decompress = lzo_decompress } } 93 }; 94 95 static int __init lzo_mod_init(void) 96 { 97 return crypto_register_alg(&alg); 98 } 99 100 static void __exit lzo_mod_fini(void) 101 { 102 crypto_unregister_alg(&alg); 103 } 104 105 module_init(lzo_mod_init); 106 module_exit(lzo_mod_fini); 107 108 MODULE_LICENSE("GPL"); 109 MODULE_DESCRIPTION("LZO Compression Algorithm"); 110 MODULE_ALIAS_CRYPTO("lzo"); 111