crypto/zlib.c - kernel/common - Git at Google

 /*
  * Cryptographic API.
  *
  * Zlib algorithm
  *
  * Copyright 2008 Sony Corporation
  *
  * Based on deflate.c, which is
  * Copyright (c) 2003 James Morris <[email protected]>
  *
  * This program is free software; you can redistribute it and/or modify it
  * under the terms of the GNU General Public License as published by the Free
  * Software Foundation; either version 2 of the License, or (at your option)
  * any later version.
  *
  * FIXME: deflate transforms will require up to a total of about 436k of kernel
  * memory on i386 (390k for compression, the rest for decompression), as the
  * current zlib kernel code uses a worst case pre-allocation system by default.
  * This needs to be fixed so that the amount of memory required is properly
  * related to the winbits and memlevel parameters.
  */

 #define pr_fmt(fmt)	"%s: " fmt, __func__

 #include <linux/init.h>
 #include <linux/module.h>
 #include <linux/zlib.h>
 #include <linux/vmalloc.h>
 #include <linux/interrupt.h>
 #include <linux/mm.h>
 #include <linux/net.h>
 #include <linux/slab.h>

 #include <crypto/internal/compress.h>

 #include <net/netlink.h>


 struct zlib_ctx {
 	struct z_stream_s comp_stream;
 	struct z_stream_s decomp_stream;
 	int decomp_windowBits;
 };


 static void zlib_comp_exit(struct zlib_ctx *ctx)
 {
 	struct z_stream_s *stream = &ctx->comp_stream;

 	if (stream->workspace) {
 		zlib_deflateEnd(stream);
 		vfree(stream->workspace);
 		stream->workspace = NULL;
 	}
 }

 static void zlib_decomp_exit(struct zlib_ctx *ctx)
 {
 	struct z_stream_s *stream = &ctx->decomp_stream;

 	if (stream->workspace) {
 		zlib_inflateEnd(stream);
 		kfree(stream->workspace);
 		stream->workspace = NULL;
 	}
 }

 static int zlib_init(struct crypto_tfm *tfm)
 {
 	return 0;
 }

 static void zlib_exit(struct crypto_tfm *tfm)
 {
 	struct zlib_ctx *ctx = crypto_tfm_ctx(tfm);

 	zlib_comp_exit(ctx);
 	zlib_decomp_exit(ctx);
 }


 static int zlib_compress_setup(struct crypto_pcomp *tfm, void *params,
 			       unsigned int len)
 {
 	struct zlib_ctx *ctx = crypto_tfm_ctx(crypto_pcomp_tfm(tfm));
 	struct z_stream_s *stream = &ctx->comp_stream;
 	struct nlattr *tb[ZLIB_COMP_MAX + 1];
 	size_t workspacesize;
 	int ret;

 	ret = nla_parse(tb, ZLIB_COMP_MAX, params, len, NULL);
 	if (ret)
 		return ret;

 	zlib_comp_exit(ctx);

 	workspacesize = zlib_deflate_workspacesize();
 	stream->workspace = vmalloc(workspacesize);
 	if (!stream->workspace)
 		return -ENOMEM;

 	memset(stream->workspace, 0, workspacesize);
 	ret = zlib_deflateInit2(stream,
 				tb[ZLIB_COMP_LEVEL]
 					? nla_get_u32(tb[ZLIB_COMP_LEVEL])
 					: Z_DEFAULT_COMPRESSION,
 				tb[ZLIB_COMP_METHOD]
 					? nla_get_u32(tb[ZLIB_COMP_METHOD])
 					: Z_DEFLATED,
 				tb[ZLIB_COMP_WINDOWBITS]
 					? nla_get_u32(tb[ZLIB_COMP_WINDOWBITS])
 					: MAX_WBITS,
 				tb[ZLIB_COMP_MEMLEVEL]
 					? nla_get_u32(tb[ZLIB_COMP_MEMLEVEL])
 					: DEF_MEM_LEVEL,
 				tb[ZLIB_COMP_STRATEGY]
 					? nla_get_u32(tb[ZLIB_COMP_STRATEGY])
 					: Z_DEFAULT_STRATEGY);
 	if (ret != Z_OK) {
 		vfree(stream->workspace);
 		stream->workspace = NULL;
 		return -EINVAL;
 	}

 	return 0;
 }

 static int zlib_compress_init(struct crypto_pcomp *tfm)
 {
 	int ret;
 	struct zlib_ctx *dctx = crypto_tfm_ctx(crypto_pcomp_tfm(tfm));
 	struct z_stream_s *stream = &dctx->comp_stream;

 	ret = zlib_deflateReset(stream);
 	if (ret != Z_OK)
 		return -EINVAL;

 	return 0;
 }

 static int zlib_compress_update(struct crypto_pcomp *tfm,
 				struct comp_request *req)
 {
 	int ret;
 	struct zlib_ctx *dctx = crypto_tfm_ctx(crypto_pcomp_tfm(tfm));
 	struct z_stream_s *stream = &dctx->comp_stream;

 	pr_debug("avail_in %u, avail_out %u\n", req->avail_in, req->avail_out);
 	stream->next_in = req->next_in;
 	stream->avail_in = req->avail_in;
 	stream->next_out = req->next_out;
 	stream->avail_out = req->avail_out;

 	ret = zlib_deflate(stream, Z_NO_FLUSH);
 	switch (ret) {
 	case Z_OK:
 		break;

 	case Z_BUF_ERROR:
 		pr_debug("zlib_deflate could not make progress\n");
 		return -EAGAIN;

 	default:
 		pr_debug("zlib_deflate failed %d\n", ret);
 		return -EINVAL;
 	}

 	ret = req->avail_out - stream->avail_out;
 	pr_debug("avail_in %u, avail_out %u (consumed %u, produced %u)\n",
 		 stream->avail_in, stream->avail_out,
 		 req->avail_in - stream->avail_in, ret);
 	req->next_in = stream->next_in;
 	req->avail_in = stream->avail_in;
 	req->next_out = stream->next_out;
 	req->avail_out = stream->avail_out;
 	return ret;
 }

 static int zlib_compress_final(struct crypto_pcomp *tfm,
 			       struct comp_request *req)
 {
 	int ret;
 	struct zlib_ctx *dctx = crypto_tfm_ctx(crypto_pcomp_tfm(tfm));
 	struct z_stream_s *stream = &dctx->comp_stream;

 	pr_debug("avail_in %u, avail_out %u\n", req->avail_in, req->avail_out);
 	stream->next_in = req->next_in;
 	stream->avail_in = req->avail_in;
 	stream->next_out = req->next_out;
 	stream->avail_out = req->avail_out;

 	ret = zlib_deflate(stream, Z_FINISH);
 	if (ret != Z_STREAM_END) {
 		pr_debug("zlib_deflate failed %d\n", ret);
 		return -EINVAL;
 	}

 	ret = req->avail_out - stream->avail_out;
 	pr_debug("avail_in %u, avail_out %u (consumed %u, produced %u)\n",
 		 stream->avail_in, stream->avail_out,
 		 req->avail_in - stream->avail_in, ret);
 	req->next_in = stream->next_in;
 	req->avail_in = stream->avail_in;
 	req->next_out = stream->next_out;
 	req->avail_out = stream->avail_out;
 	return ret;
 }


 static int zlib_decompress_setup(struct crypto_pcomp *tfm, void *params,
 				 unsigned int len)
 {
 	struct zlib_ctx *ctx = crypto_tfm_ctx(crypto_pcomp_tfm(tfm));
 	struct z_stream_s *stream = &ctx->decomp_stream;
 	struct nlattr *tb[ZLIB_DECOMP_MAX + 1];
 	int ret = 0;

 	ret = nla_parse(tb, ZLIB_DECOMP_MAX, params, len, NULL);
 	if (ret)
 		return ret;

 	zlib_decomp_exit(ctx);

 	ctx->decomp_windowBits = tb[ZLIB_DECOMP_WINDOWBITS]
 				 ? nla_get_u32(tb[ZLIB_DECOMP_WINDOWBITS])
 				 : DEF_WBITS;

 	stream->workspace = kzalloc(zlib_inflate_workspacesize(), GFP_KERNEL);
 	if (!stream->workspace)
 		return -ENOMEM;

 	ret = zlib_inflateInit2(stream, ctx->decomp_windowBits);
 	if (ret != Z_OK) {
 		kfree(stream->workspace);
 		stream->workspace = NULL;
 		return -EINVAL;
 	}

 	return 0;
 }

 static int zlib_decompress_init(struct crypto_pcomp *tfm)
 {
 	int ret;
 	struct zlib_ctx *dctx = crypto_tfm_ctx(crypto_pcomp_tfm(tfm));
 	struct z_stream_s *stream = &dctx->decomp_stream;

 	ret = zlib_inflateReset(stream);
 	if (ret != Z_OK)
 		return -EINVAL;

 	return 0;
 }

 static int zlib_decompress_update(struct crypto_pcomp *tfm,
 				  struct comp_request *req)
 {
 	int ret;
 	struct zlib_ctx *dctx = crypto_tfm_ctx(crypto_pcomp_tfm(tfm));
 	struct z_stream_s *stream = &dctx->decomp_stream;

 	pr_debug("avail_in %u, avail_out %u\n", req->avail_in, req->avail_out);
 	stream->next_in = req->next_in;
 	stream->avail_in = req->avail_in;
 	stream->next_out = req->next_out;
 	stream->avail_out = req->avail_out;

 	ret = zlib_inflate(stream, Z_SYNC_FLUSH);
 	switch (ret) {
 	case Z_OK:
 	case Z_STREAM_END:
 		break;

 	case Z_BUF_ERROR:
 		pr_debug("zlib_inflate could not make progress\n");
 		return -EAGAIN;

 	default:
 		pr_debug("zlib_inflate failed %d\n", ret);
 		return -EINVAL;
 	}

 	ret = req->avail_out - stream->avail_out;
 	pr_debug("avail_in %u, avail_out %u (consumed %u, produced %u)\n",
 		 stream->avail_in, stream->avail_out,
 		 req->avail_in - stream->avail_in, ret);
 	req->next_in = stream->next_in;
 	req->avail_in = stream->avail_in;
 	req->next_out = stream->next_out;
 	req->avail_out = stream->avail_out;
 	return ret;
 }

 static int zlib_decompress_final(struct crypto_pcomp *tfm,
 				 struct comp_request *req)
 {
 	int ret;
 	struct zlib_ctx *dctx = crypto_tfm_ctx(crypto_pcomp_tfm(tfm));
 	struct z_stream_s *stream = &dctx->decomp_stream;

 	pr_debug("avail_in %u, avail_out %u\n", req->avail_in, req->avail_out);
 	stream->next_in = req->next_in;
 	stream->avail_in = req->avail_in;
 	stream->next_out = req->next_out;
 	stream->avail_out = req->avail_out;

 	if (dctx->decomp_windowBits < 0) {
 		ret = zlib_inflate(stream, Z_SYNC_FLUSH);
 		/*
 		 * Work around a bug in zlib, which sometimes wants to taste an
 		 * extra byte when being used in the (undocumented) raw deflate
 		 * mode. (From USAGI).
 		 */
 		if (ret == Z_OK && !stream->avail_in && stream->avail_out) {
 			const void *saved_next_in = stream->next_in;
 			u8 zerostuff = 0;

 			stream->next_in = &zerostuff;
 			stream->avail_in = 1;
 			ret = zlib_inflate(stream, Z_FINISH);
 			stream->next_in = saved_next_in;
 			stream->avail_in = 0;
 		}
 	} else
 		ret = zlib_inflate(stream, Z_FINISH);
 	if (ret != Z_STREAM_END) {
 		pr_debug("zlib_inflate failed %d\n", ret);
 		return -EINVAL;
 	}

 	ret = req->avail_out - stream->avail_out;
 	pr_debug("avail_in %u, avail_out %u (consumed %u, produced %u)\n",
 		 stream->avail_in, stream->avail_out,
 		 req->avail_in - stream->avail_in, ret);
 	req->next_in = stream->next_in;
 	req->avail_in = stream->avail_in;
 	req->next_out = stream->next_out;
 	req->avail_out = stream->avail_out;
 	return ret;
 }


 static struct pcomp_alg zlib_alg = {
 	.compress_setup		= zlib_compress_setup,
 	.compress_init		= zlib_compress_init,
 	.compress_update	= zlib_compress_update,
 	.compress_final		= zlib_compress_final,
 	.decompress_setup	= zlib_decompress_setup,
 	.decompress_init	= zlib_decompress_init,
 	.decompress_update	= zlib_decompress_update,
 	.decompress_final	= zlib_decompress_final,

 	.base			= {
 		.cra_name	= "zlib",
 		.cra_flags	= CRYPTO_ALG_TYPE_PCOMPRESS,
 		.cra_ctxsize	= sizeof(struct zlib_ctx),
 		.cra_module	= THIS_MODULE,
 		.cra_init	= zlib_init,
 		.cra_exit	= zlib_exit,
 	}
 };

 static int __init zlib_mod_init(void)
 {
 	return crypto_register_pcomp(&zlib_alg);
 }

 static void __exit zlib_mod_fini(void)
 {
 	crypto_unregister_pcomp(&zlib_alg);
 }

 module_init(zlib_mod_init);
 module_exit(zlib_mod_fini);

 MODULE_LICENSE("GPL");
 MODULE_DESCRIPTION("Zlib Compression Algorithm");
 MODULE_AUTHOR("Sony Corporation");
	/*
	* Cryptographic API.
	*
	* Zlib algorithm
	*
	* Copyright 2008 Sony Corporation
	*
	* Based on deflate.c, which is
	* Copyright (c) 2003 James Morris <[email protected]>
	*
	* This program is free software; you can redistribute it and/or modify it
	* under the terms of the GNU General Public License as published by the Free
	* Software Foundation; either version 2 of the License, or (at your option)
	* any later version.
	*
	* FIXME: deflate transforms will require up to a total of about 436k of kernel
	* memory on i386 (390k for compression, the rest for decompression), as the
	* current zlib kernel code uses a worst case pre-allocation system by default.
	* This needs to be fixed so that the amount of memory required is properly
	* related to the winbits and memlevel parameters.
	*/

	#define pr_fmt(fmt) "%s: " fmt, __func__

	#include <linux/init.h>
	#include <linux/module.h>
	#include <linux/zlib.h>
	#include <linux/vmalloc.h>
	#include <linux/interrupt.h>
	#include <linux/mm.h>
	#include <linux/net.h>
	#include <linux/slab.h>

	#include <crypto/internal/compress.h>

	#include <net/netlink.h>


	struct zlib_ctx {
	struct z_stream_s comp_stream;
	struct z_stream_s decomp_stream;
	int decomp_windowBits;
	};


	static void zlib_comp_exit(struct zlib_ctx *ctx)
	{
	struct z_stream_s *stream = &ctx->comp_stream;

	if (stream->workspace) {
	zlib_deflateEnd(stream);
	vfree(stream->workspace);
	stream->workspace = NULL;
	}
	}

	static void zlib_decomp_exit(struct zlib_ctx *ctx)
	{
	struct z_stream_s *stream = &ctx->decomp_stream;

	if (stream->workspace) {
	zlib_inflateEnd(stream);
	kfree(stream->workspace);
	stream->workspace = NULL;
	}
	}

	static int zlib_init(struct crypto_tfm *tfm)
	{
	return 0;
	}

	static void zlib_exit(struct crypto_tfm *tfm)
	{
	struct zlib_ctx *ctx = crypto_tfm_ctx(tfm);

	zlib_comp_exit(ctx);
	zlib_decomp_exit(ctx);
	}


	static int zlib_compress_setup(struct crypto_pcomp tfm, void params,
	unsigned int len)
	{
	struct zlib_ctx *ctx = crypto_tfm_ctx(crypto_pcomp_tfm(tfm));
	struct z_stream_s *stream = &ctx->comp_stream;
	struct nlattr *tb[ZLIB_COMP_MAX + 1];
	size_t workspacesize;
	int ret;

	ret = nla_parse(tb, ZLIB_COMP_MAX, params, len, NULL);
	if (ret)
	return ret;

	zlib_comp_exit(ctx);

	workspacesize = zlib_deflate_workspacesize();
	stream->workspace = vmalloc(workspacesize);
	if (!stream->workspace)
	return -ENOMEM;

	memset(stream->workspace, 0, workspacesize);
	ret = zlib_deflateInit2(stream,
	tb[ZLIB_COMP_LEVEL]
	? nla_get_u32(tb[ZLIB_COMP_LEVEL])
	: Z_DEFAULT_COMPRESSION,
	tb[ZLIB_COMP_METHOD]
	? nla_get_u32(tb[ZLIB_COMP_METHOD])
	: Z_DEFLATED,
	tb[ZLIB_COMP_WINDOWBITS]
	? nla_get_u32(tb[ZLIB_COMP_WINDOWBITS])
	: MAX_WBITS,
	tb[ZLIB_COMP_MEMLEVEL]
	? nla_get_u32(tb[ZLIB_COMP_MEMLEVEL])
	: DEF_MEM_LEVEL,
	tb[ZLIB_COMP_STRATEGY]
	? nla_get_u32(tb[ZLIB_COMP_STRATEGY])
	: Z_DEFAULT_STRATEGY);
	if (ret != Z_OK) {
	vfree(stream->workspace);
	stream->workspace = NULL;
	return -EINVAL;
	}

	return 0;
	}

	static int zlib_compress_init(struct crypto_pcomp *tfm)
	{
	int ret;
	struct zlib_ctx *dctx = crypto_tfm_ctx(crypto_pcomp_tfm(tfm));
	struct z_stream_s *stream = &dctx->comp_stream;

	ret = zlib_deflateReset(stream);
	if (ret != Z_OK)
	return -EINVAL;

	return 0;
	}

	static int zlib_compress_update(struct crypto_pcomp *tfm,
	struct comp_request *req)
	{
	int ret;
	struct zlib_ctx *dctx = crypto_tfm_ctx(crypto_pcomp_tfm(tfm));
	struct z_stream_s *stream = &dctx->comp_stream;

	pr_debug("avail_in %u, avail_out %u\n", req->avail_in, req->avail_out);
	stream->next_in = req->next_in;
	stream->avail_in = req->avail_in;
	stream->next_out = req->next_out;
	stream->avail_out = req->avail_out;

	ret = zlib_deflate(stream, Z_NO_FLUSH);
	switch (ret) {
	case Z_OK:
	break;

	case Z_BUF_ERROR:
	pr_debug("zlib_deflate could not make progress\n");
	return -EAGAIN;

	default:
	pr_debug("zlib_deflate failed %d\n", ret);
	return -EINVAL;
	}

	ret = req->avail_out - stream->avail_out;
	pr_debug("avail_in %u, avail_out %u (consumed %u, produced %u)\n",
	stream->avail_in, stream->avail_out,
	req->avail_in - stream->avail_in, ret);
	req->next_in = stream->next_in;
	req->avail_in = stream->avail_in;
	req->next_out = stream->next_out;
	req->avail_out = stream->avail_out;
	return ret;
	}

	static int zlib_compress_final(struct crypto_pcomp *tfm,
	struct comp_request *req)
	{
	int ret;
	struct zlib_ctx *dctx = crypto_tfm_ctx(crypto_pcomp_tfm(tfm));
	struct z_stream_s *stream = &dctx->comp_stream;

	pr_debug("avail_in %u, avail_out %u\n", req->avail_in, req->avail_out);
	stream->next_in = req->next_in;
	stream->avail_in = req->avail_in;
	stream->next_out = req->next_out;
	stream->avail_out = req->avail_out;

	ret = zlib_deflate(stream, Z_FINISH);
	if (ret != Z_STREAM_END) {
	pr_debug("zlib_deflate failed %d\n", ret);
	return -EINVAL;
	}

	ret = req->avail_out - stream->avail_out;
	pr_debug("avail_in %u, avail_out %u (consumed %u, produced %u)\n",
	stream->avail_in, stream->avail_out,
	req->avail_in - stream->avail_in, ret);
	req->next_in = stream->next_in;
	req->avail_in = stream->avail_in;
	req->next_out = stream->next_out;
	req->avail_out = stream->avail_out;
	return ret;
	}


	static int zlib_decompress_setup(struct crypto_pcomp tfm, void params,
	unsigned int len)
	{
	struct zlib_ctx *ctx = crypto_tfm_ctx(crypto_pcomp_tfm(tfm));
	struct z_stream_s *stream = &ctx->decomp_stream;
	struct nlattr *tb[ZLIB_DECOMP_MAX + 1];
	int ret = 0;

	ret = nla_parse(tb, ZLIB_DECOMP_MAX, params, len, NULL);
	if (ret)
	return ret;

	zlib_decomp_exit(ctx);

	ctx->decomp_windowBits = tb[ZLIB_DECOMP_WINDOWBITS]
	? nla_get_u32(tb[ZLIB_DECOMP_WINDOWBITS])
	: DEF_WBITS;

	stream->workspace = kzalloc(zlib_inflate_workspacesize(), GFP_KERNEL);
	if (!stream->workspace)
	return -ENOMEM;

	ret = zlib_inflateInit2(stream, ctx->decomp_windowBits);
	if (ret != Z_OK) {
	kfree(stream->workspace);
	stream->workspace = NULL;
	return -EINVAL;
	}

	return 0;
	}

	static int zlib_decompress_init(struct crypto_pcomp *tfm)
	{
	int ret;
	struct zlib_ctx *dctx = crypto_tfm_ctx(crypto_pcomp_tfm(tfm));
	struct z_stream_s *stream = &dctx->decomp_stream;

	ret = zlib_inflateReset(stream);
	if (ret != Z_OK)
	return -EINVAL;

	return 0;
	}

	static int zlib_decompress_update(struct crypto_pcomp *tfm,
	struct comp_request *req)
	{
	int ret;
	struct zlib_ctx *dctx = crypto_tfm_ctx(crypto_pcomp_tfm(tfm));
	struct z_stream_s *stream = &dctx->decomp_stream;

	pr_debug("avail_in %u, avail_out %u\n", req->avail_in, req->avail_out);
	stream->next_in = req->next_in;
	stream->avail_in = req->avail_in;
	stream->next_out = req->next_out;
	stream->avail_out = req->avail_out;

	ret = zlib_inflate(stream, Z_SYNC_FLUSH);
	switch (ret) {
	case Z_OK:
	case Z_STREAM_END:
	break;

	case Z_BUF_ERROR:
	pr_debug("zlib_inflate could not make progress\n");
	return -EAGAIN;

	default:
	pr_debug("zlib_inflate failed %d\n", ret);
	return -EINVAL;
	}

	ret = req->avail_out - stream->avail_out;
	pr_debug("avail_in %u, avail_out %u (consumed %u, produced %u)\n",
	stream->avail_in, stream->avail_out,
	req->avail_in - stream->avail_in, ret);
	req->next_in = stream->next_in;
	req->avail_in = stream->avail_in;
	req->next_out = stream->next_out;
	req->avail_out = stream->avail_out;
	return ret;
	}

	static int zlib_decompress_final(struct crypto_pcomp *tfm,
	struct comp_request *req)
	{
	int ret;
	struct zlib_ctx *dctx = crypto_tfm_ctx(crypto_pcomp_tfm(tfm));
	struct z_stream_s *stream = &dctx->decomp_stream;

	pr_debug("avail_in %u, avail_out %u\n", req->avail_in, req->avail_out);
	stream->next_in = req->next_in;
	stream->avail_in = req->avail_in;
	stream->next_out = req->next_out;
	stream->avail_out = req->avail_out;

	if (dctx->decomp_windowBits < 0) {
	ret = zlib_inflate(stream, Z_SYNC_FLUSH);
	/*
	* Work around a bug in zlib, which sometimes wants to taste an
	* extra byte when being used in the (undocumented) raw deflate
	* mode. (From USAGI).
	*/
	if (ret == Z_OK && !stream->avail_in && stream->avail_out) {
	const void *saved_next_in = stream->next_in;
	u8 zerostuff = 0;

	stream->next_in = &zerostuff;
	stream->avail_in = 1;
	ret = zlib_inflate(stream, Z_FINISH);
	stream->next_in = saved_next_in;
	stream->avail_in = 0;
	}
	} else
	ret = zlib_inflate(stream, Z_FINISH);
	if (ret != Z_STREAM_END) {
	pr_debug("zlib_inflate failed %d\n", ret);
	return -EINVAL;
	}

	ret = req->avail_out - stream->avail_out;
	pr_debug("avail_in %u, avail_out %u (consumed %u, produced %u)\n",
	stream->avail_in, stream->avail_out,
	req->avail_in - stream->avail_in, ret);
	req->next_in = stream->next_in;
	req->avail_in = stream->avail_in;
	req->next_out = stream->next_out;
	req->avail_out = stream->avail_out;
	return ret;
	}


	static struct pcomp_alg zlib_alg = {
	.compress_setup = zlib_compress_setup,
	.compress_init = zlib_compress_init,
	.compress_update = zlib_compress_update,
	.compress_final = zlib_compress_final,
	.decompress_setup = zlib_decompress_setup,
	.decompress_init = zlib_decompress_init,
	.decompress_update = zlib_decompress_update,
	.decompress_final = zlib_decompress_final,

	.base = {
	.cra_name = "zlib",
	.cra_flags = CRYPTO_ALG_TYPE_PCOMPRESS,
	.cra_ctxsize = sizeof(struct zlib_ctx),
	.cra_module = THIS_MODULE,
	.cra_init = zlib_init,
	.cra_exit = zlib_exit,
	}
	};

	static int __init zlib_mod_init(void)
	{
	return crypto_register_pcomp(&zlib_alg);
	}

	static void __exit zlib_mod_fini(void)
	{
	crypto_unregister_pcomp(&zlib_alg);
	}

	module_init(zlib_mod_init);
	module_exit(zlib_mod_fini);

	MODULE_LICENSE("GPL");
	MODULE_DESCRIPTION("Zlib Compression Algorithm");
	MODULE_AUTHOR("Sony Corporation");