openwrt/target/linux/generic/patches-4.3/540-crypto-xz-decompression-support.patch

--- a/crypto/Kconfig
+++ b/crypto/Kconfig
@@ -1536,6 +1536,13 @@ config CRYPTO_LZ4HC
 	help
 	  This is the LZ4 high compression mode algorithm.
 
+config CRYPTO_XZ
+	tristate "XZ compression algorithm"
+	select CRYPTO_ALGAPI
+	select XZ_DEC
+	help
+	  This is the XZ algorithm. Only decompression is supported for now.
+
 comment "Random Number Generation"
 
 config CRYPTO_ANSI_CPRNG
--- a/crypto/Makefile
+++ b/crypto/Makefile
@@ -103,6 +103,7 @@ obj-$(CONFIG_CRYPTO_AUTHENC) += authenc.
 obj-$(CONFIG_CRYPTO_LZO) += lzo.o
 obj-$(CONFIG_CRYPTO_LZ4) += lz4.o
 obj-$(CONFIG_CRYPTO_LZ4HC) += lz4hc.o
+obj-$(CONFIG_CRYPTO_XZ) += xz.o
 obj-$(CONFIG_CRYPTO_842) += 842.o
 obj-$(CONFIG_CRYPTO_RNG2) += rng.o
 obj-$(CONFIG_CRYPTO_ANSI_CPRNG) += ansi_cprng.o
--- /dev/null
+++ b/crypto/xz.c
@@ -0,0 +1,117 @@
+/*
+ * Cryptographic API.
+ *
+ * XZ decompression support.
+ *
+ * Copyright (c) 2012 Gabor Juhos <juhosg@openwrt.org>
+ *
+ * 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.
+ *
+ */
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/crypto.h>
+#include <linux/xz.h>
+#include <linux/interrupt.h>
+#include <linux/mm.h>
+#include <linux/net.h>
+
+struct xz_comp_ctx {
+	struct xz_dec	*decomp_state;
+	struct xz_buf	decomp_buf;
+};
+
+static int crypto_xz_decomp_init(struct xz_comp_ctx *ctx)
+{
+	ctx->decomp_state = xz_dec_init(XZ_SINGLE, 0);
+	if (!ctx->decomp_state)
+		return -ENOMEM;
+
+	return 0;
+}
+
+static void crypto_xz_decomp_exit(struct xz_comp_ctx *ctx)
+{
+	xz_dec_end(ctx->decomp_state);
+}
+
+static int crypto_xz_init(struct crypto_tfm *tfm)
+{
+	struct xz_comp_ctx *ctx = crypto_tfm_ctx(tfm);
+
+	return crypto_xz_decomp_init(ctx);
+}
+
+static void crypto_xz_exit(struct crypto_tfm *tfm)
+{
+	struct xz_comp_ctx *ctx = crypto_tfm_ctx(tfm);
+
+	crypto_xz_decomp_exit(ctx);
+}
+
+static int crypto_xz_compress(struct crypto_tfm *tfm, const u8 *src,
+			      unsigned int slen, u8 *dst, unsigned int *dlen)
+{
+	return -EOPNOTSUPP;
+}
+
+static int crypto_xz_decompress(struct crypto_tfm *tfm, const u8 *src,
+				unsigned int slen, u8 *dst, unsigned int *dlen)
+{
+	struct xz_comp_ctx *dctx = crypto_tfm_ctx(tfm);
+	struct xz_buf *xz_buf = &dctx->decomp_buf;
+	int ret;
+
+	memset(xz_buf, '\0', sizeof(struct xz_buf));
+
+	xz_buf->in = (u8 *) src;
+	xz_buf->in_pos = 0;
+	xz_buf->in_size = slen;
+	xz_buf->out = (u8 *) dst;
+	xz_buf->out_pos = 0;
+	xz_buf->out_size = *dlen;
+
+	ret = xz_dec_run(dctx->decomp_state, xz_buf);
+	if (ret != XZ_STREAM_END) {
+		ret = -EINVAL;
+		goto out;
+	}
+
+	*dlen = xz_buf->out_pos;
+	ret = 0;
+
+out:
+	return ret;
+}
+
+static struct crypto_alg crypto_xz_alg = {
+	.cra_name		= "xz",
+	.cra_flags		= CRYPTO_ALG_TYPE_COMPRESS,
+	.cra_ctxsize		= sizeof(struct xz_comp_ctx),
+	.cra_module		= THIS_MODULE,
+	.cra_list		= LIST_HEAD_INIT(crypto_xz_alg.cra_list),
+	.cra_init		= crypto_xz_init,
+	.cra_exit		= crypto_xz_exit,
+	.cra_u			= { .compress = {
+	.coa_compress 		= crypto_xz_compress,
+	.coa_decompress  	= crypto_xz_decompress } }
+};
+
+static int __init crypto_xz_mod_init(void)
+{
+	return crypto_register_alg(&crypto_xz_alg);
+}
+
+static void __exit crypto_xz_mod_exit(void)
+{
+	crypto_unregister_alg(&crypto_xz_alg);
+}
+
+module_init(crypto_xz_mod_init);
+module_exit(crypto_xz_mod_exit);
+
+MODULE_LICENSE("GPL v2");
+MODULE_DESCRIPTION("Crypto XZ decompression support");
+MODULE_AUTHOR("Gabor Juhos <juhosg@openwrt.org>");