crypto: add lz4 Cryptographic API

Add support for lz4 and lz4hc compression algorithm using the lib/lz4/*
codebase.

[akpm@linux-foundation.org: fix warnings]
Signed-off-by: Chanho Min <chanho.min@lge.com>
Cc: "Darrick J. Wong" <djwong@us.ibm.com>
Cc: Bob Pearson <rpearson@systemfabricworks.com>
Cc: Richard Weinberger <richard@nod.at>
Cc: Herbert Xu <herbert@gondor.hengli.com.au>
Cc: Yann Collet <yann.collet.73@gmail.com>
Cc: Kyungsik Lee <kyungsik.lee@lge.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 106 insertions, 0 deletions

diff --git a/crypto/lz4.c b/crypto/lz4.c
new file mode 100644
index 0000000..4586dd1
--- /dev/null
+++ b/crypto/lz4.c
@@ -0,0 +1,106 @@
+/*
+ * Cryptographic API.
+ *
+ * Copyright (c) 2013 Chanho Min <chanho.min@lge.com>
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 as published by
+ * the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License along with
+ * this program; if not, write to the Free Software Foundation, Inc., 51
+ * Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
+ *
+ */
+
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/crypto.h>
+#include <linux/vmalloc.h>
+#include <linux/lz4.h>
+
+struct lz4_ctx {
+	void *lz4_comp_mem;
+};
+
+static int lz4_init(struct crypto_tfm *tfm)
+{
+	struct lz4_ctx *ctx = crypto_tfm_ctx(tfm);
+
+	ctx->lz4_comp_mem = vmalloc(LZ4_MEM_COMPRESS);
+	if (!ctx->lz4_comp_mem)
+		return -ENOMEM;
+
+	return 0;
+}
+
+static void lz4_exit(struct crypto_tfm *tfm)
+{
+	struct lz4_ctx *ctx = crypto_tfm_ctx(tfm);
+	vfree(ctx->lz4_comp_mem);
+}
+
+static int lz4_compress_crypto(struct crypto_tfm *tfm, const u8 *src,
+			    unsigned int slen, u8 *dst, unsigned int *dlen)
+{
+	struct lz4_ctx *ctx = crypto_tfm_ctx(tfm);
+	size_t tmp_len = *dlen;
+	int err;
+
+	err = lz4_compress(src, slen, dst, &tmp_len, ctx->lz4_comp_mem);
+
+	if (err < 0)
+		return -EINVAL;
+
+	*dlen = tmp_len;
+	return 0;
+}
+
+static int lz4_decompress_crypto(struct crypto_tfm *tfm, const u8 *src,
+			      unsigned int slen, u8 *dst, unsigned int *dlen)
+{
+	int err;
+	size_t tmp_len = *dlen;
+	size_t __slen = slen;
+
+	err = lz4_decompress(src, &__slen, dst, tmp_len);
+	if (err < 0)
+		return -EINVAL;
+
+	*dlen = tmp_len;
+	return err;
+}
+
+static struct crypto_alg alg_lz4 = {
+	.cra_name		= "lz4",
+	.cra_flags		= CRYPTO_ALG_TYPE_COMPRESS,
+	.cra_ctxsize		= sizeof(struct lz4_ctx),
+	.cra_module		= THIS_MODULE,
+	.cra_list		= LIST_HEAD_INIT(alg_lz4.cra_list),
+	.cra_init		= lz4_init,
+	.cra_exit		= lz4_exit,
+	.cra_u			= { .compress = {
+	.coa_compress		= lz4_compress_crypto,
+	.coa_decompress		= lz4_decompress_crypto } }
+};
+
+static int __init lz4_mod_init(void)
+{
+	return crypto_register_alg(&alg_lz4);
+}
+
+static void __exit lz4_mod_fini(void)
+{
+	crypto_unregister_alg(&alg_lz4);
+}
+
+module_init(lz4_mod_init);
+module_exit(lz4_mod_fini);
+
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("LZ4 Compression Algorithm");