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/lzo.h>
 24
 25struct lzo_ctx {
 26	void *lzo_comp_mem;
 27};
 28
 29static int lzo_init(struct crypto_tfm *tfm)
 30{
 31	struct lzo_ctx *ctx = crypto_tfm_ctx(tfm);
 32
 33	ctx->lzo_comp_mem = vmalloc(LZO1X_MEM_COMPRESS);
 34	if (!ctx->lzo_comp_mem)
 35		return -ENOMEM;
 36
 37	return 0;
 38}
 39
 40static void lzo_exit(struct crypto_tfm *tfm)
 41{
 42	struct lzo_ctx *ctx = crypto_tfm_ctx(tfm);
 43
 44	vfree(ctx->lzo_comp_mem);
 45}
 46
 47static int lzo_compress(struct crypto_tfm *tfm, const u8 *src,
 48			    unsigned int slen, u8 *dst, unsigned int *dlen)
 49{
 50	struct lzo_ctx *ctx = crypto_tfm_ctx(tfm);
 51	size_t tmp_len = *dlen; /* size_t(ulong) <-> uint on 64 bit */
 52	int err;
 53
 54	err = lzo1x_1_compress(src, slen, dst, &tmp_len, ctx->lzo_comp_mem);
 55
 56	if (err != LZO_E_OK)
 57		return -EINVAL;
 58
 59	*dlen = tmp_len;
 60	return 0;
 61}
 62
 63static int lzo_decompress(struct crypto_tfm *tfm, const u8 *src,
 64			      unsigned int slen, u8 *dst, unsigned int *dlen)
 65{
 66	int err;
 67	size_t tmp_len = *dlen; /* size_t(ulong) <-> uint on 64 bit */
 68
 69	err = lzo1x_decompress_safe(src, slen, dst, &tmp_len);
 70
 71	if (err != LZO_E_OK)
 72		return -EINVAL;
 73
 74	*dlen = tmp_len;
 75	return 0;
 76
 77}
 78
 79static struct crypto_alg alg = {
 80	.cra_name		= "lzo",
 81	.cra_flags		= CRYPTO_ALG_TYPE_COMPRESS,
 82	.cra_ctxsize		= sizeof(struct lzo_ctx),
 83	.cra_module		= THIS_MODULE,
 84	.cra_list		= LIST_HEAD_INIT(alg.cra_list),
 85	.cra_init		= lzo_init,
 86	.cra_exit		= lzo_exit,
 87	.cra_u			= { .compress = {
 88	.coa_compress 		= lzo_compress,
 89	.coa_decompress  	= lzo_decompress } }
 90};
 91
 92static int __init lzo_mod_init(void)
 93{
 94	return crypto_register_alg(&alg);
 95}
 96
 97static void __exit lzo_mod_fini(void)
 98{
 99	crypto_unregister_alg(&alg);
100}
101
102module_init(lzo_mod_init);
103module_exit(lzo_mod_fini);
104
105MODULE_LICENSE("GPL");
106MODULE_DESCRIPTION("LZO Compression Algorithm");