crypto/deflate.c - linux - Git at Google

 /*
  * Cryptographic API.
  *
  * Deflate algorithm (RFC 1951), implemented here primarily for use
  * by IPCOMP (RFC 3173 & RFC 2394).
  *
  * Copyright (c) 2003 James Morris <jmorris@intercode.com.au>
  *
  * 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.
  *
  * The default winbits of 11 should suit most packets, and it may be something
  * to configure on a per-tfm basis in the future.
  *
  * Currently, compression history is not maintained between tfm calls, as
  * it is not needed for IPCOMP and keeps the code simpler.  It can be
  * implemented if someone wants it.
  */
 #include <linux/init.h>
 #include <linux/module.h>
 #include <linux/crypto.h>
 #include <linux/zlib.h>
 #include <linux/vmalloc.h>
 #include <linux/interrupt.h>
 #include <linux/mm.h>
 #include <linux/net.h>
 #include <crypto/internal/scompress.h>

 #define DEFLATE_DEF_LEVEL		Z_DEFAULT_COMPRESSION
 #define DEFLATE_DEF_WINBITS		11
 #define DEFLATE_DEF_MEMLEVEL		MAX_MEM_LEVEL

 struct deflate_ctx {
 	struct z_stream_s comp_stream;
 	struct z_stream_s decomp_stream;
 };

 static int deflate_comp_init(struct deflate_ctx *ctx, int format)
 {
 	int ret = 0;
 	struct z_stream_s *stream = &ctx->comp_stream;

 	stream->workspace = vzalloc(zlib_deflate_workspacesize(
 				    MAX_WBITS, MAX_MEM_LEVEL));
 	if (!stream->workspace) {
 		ret = -ENOMEM;
 		goto out;
 	}
 	if (format)
 		ret = zlib_deflateInit(stream, 3);
 	else
 		ret = zlib_deflateInit2(stream, DEFLATE_DEF_LEVEL, Z_DEFLATED,
 					-DEFLATE_DEF_WINBITS,
 					DEFLATE_DEF_MEMLEVEL,
 					Z_DEFAULT_STRATEGY);
 	if (ret != Z_OK) {
 		ret = -EINVAL;
 		goto out_free;
 	}
 out:
 	return ret;
 out_free:
 	vfree(stream->workspace);
 	goto out;
 }

 static int deflate_decomp_init(struct deflate_ctx *ctx, int format)
 {
 	int ret = 0;
 	struct z_stream_s *stream = &ctx->decomp_stream;

 	stream->workspace = vzalloc(zlib_inflate_workspacesize());
 	if (!stream->workspace) {
 		ret = -ENOMEM;
 		goto out;
 	}
 	if (format)
 		ret = zlib_inflateInit(stream);
 	else
 		ret = zlib_inflateInit2(stream, -DEFLATE_DEF_WINBITS);
 	if (ret != Z_OK) {
 		ret = -EINVAL;
 		goto out_free;
 	}
 out:
 	return ret;
 out_free:
 	vfree(stream->workspace);
 	goto out;
 }

 static void deflate_comp_exit(struct deflate_ctx *ctx)
 {
 	zlib_deflateEnd(&ctx->comp_stream);
 	vfree(ctx->comp_stream.workspace);
 }

 static void deflate_decomp_exit(struct deflate_ctx *ctx)
 {
 	zlib_inflateEnd(&ctx->decomp_stream);
 	vfree(ctx->decomp_stream.workspace);
 }

 static int __deflate_init(void *ctx, int format)
 {
 	int ret;

 	ret = deflate_comp_init(ctx, format);
 	if (ret)
 		goto out;
 	ret = deflate_decomp_init(ctx, format);
 	if (ret)
 		deflate_comp_exit(ctx);
 out:
 	return ret;
 }

 static void *gen_deflate_alloc_ctx(struct crypto_scomp *tfm, int format)
 {
 	struct deflate_ctx *ctx;
 	int ret;

 	ctx = kzalloc(sizeof(*ctx), GFP_KERNEL);
 	if (!ctx)
 		return ERR_PTR(-ENOMEM);

 	ret = __deflate_init(ctx, format);
 	if (ret) {
 		kfree(ctx);
 		return ERR_PTR(ret);
 	}

 	return ctx;
 }

 static void *deflate_alloc_ctx(struct crypto_scomp *tfm)
 {
 	return gen_deflate_alloc_ctx(tfm, 0);
 }

 static void *zlib_deflate_alloc_ctx(struct crypto_scomp *tfm)
 {
 	return gen_deflate_alloc_ctx(tfm, 1);
 }

 static int deflate_init(struct crypto_tfm *tfm)
 {
 	struct deflate_ctx *ctx = crypto_tfm_ctx(tfm);

 	return __deflate_init(ctx, 0);
 }

 static void __deflate_exit(void *ctx)
 {
 	deflate_comp_exit(ctx);
 	deflate_decomp_exit(ctx);
 }

 static void deflate_free_ctx(struct crypto_scomp *tfm, void *ctx)
 {
 	__deflate_exit(ctx);
 	kzfree(ctx);
 }

 static void deflate_exit(struct crypto_tfm *tfm)
 {
 	struct deflate_ctx *ctx = crypto_tfm_ctx(tfm);

 	__deflate_exit(ctx);
 }

 static int __deflate_compress(const u8 *src, unsigned int slen,
 			      u8 *dst, unsigned int *dlen, void *ctx)
 {
 	int ret = 0;
 	struct deflate_ctx *dctx = ctx;
 	struct z_stream_s *stream = &dctx->comp_stream;

 	ret = zlib_deflateReset(stream);
 	if (ret != Z_OK) {
 		ret = -EINVAL;
 		goto out;
 	}

 	stream->next_in = (u8 *)src;
 	stream->avail_in = slen;
 	stream->next_out = (u8 *)dst;
 	stream->avail_out = *dlen;

 	ret = zlib_deflate(stream, Z_FINISH);
 	if (ret != Z_STREAM_END) {
 		ret = -EINVAL;
 		goto out;
 	}
 	ret = 0;
 	*dlen = stream->total_out;
 out:
 	return ret;
 }

 static int deflate_compress(struct crypto_tfm *tfm, const u8 *src,
 			    unsigned int slen, u8 *dst, unsigned int *dlen)
 {
 	struct deflate_ctx *dctx = crypto_tfm_ctx(tfm);

 	return __deflate_compress(src, slen, dst, dlen, dctx);
 }

 static int deflate_scompress(struct crypto_scomp *tfm, const u8 *src,
 			     unsigned int slen, u8 *dst, unsigned int *dlen,
 			     void *ctx)
 {
 	return __deflate_compress(src, slen, dst, dlen, ctx);
 }

 static int __deflate_decompress(const u8 *src, unsigned int slen,
 				u8 *dst, unsigned int *dlen, void *ctx)
 {

 	int ret = 0;
 	struct deflate_ctx *dctx = ctx;
 	struct z_stream_s *stream = &dctx->decomp_stream;

 	ret = zlib_inflateReset(stream);
 	if (ret != Z_OK) {
 		ret = -EINVAL;
 		goto out;
 	}

 	stream->next_in = (u8 *)src;
 	stream->avail_in = slen;
 	stream->next_out = (u8 *)dst;
 	stream->avail_out = *dlen;

 	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) {
 		u8 zerostuff = 0;
 		stream->next_in = &zerostuff;
 		stream->avail_in = 1;
 		ret = zlib_inflate(stream, Z_FINISH);
 	}
 	if (ret != Z_STREAM_END) {
 		ret = -EINVAL;
 		goto out;
 	}
 	ret = 0;
 	*dlen = stream->total_out;
 out:
 	return ret;
 }

 static int deflate_decompress(struct crypto_tfm *tfm, const u8 *src,
 			      unsigned int slen, u8 *dst, unsigned int *dlen)
 {
 	struct deflate_ctx *dctx = crypto_tfm_ctx(tfm);

 	return __deflate_decompress(src, slen, dst, dlen, dctx);
 }

 static int deflate_sdecompress(struct crypto_scomp *tfm, const u8 *src,
 			       unsigned int slen, u8 *dst, unsigned int *dlen,
 			       void *ctx)
 {
 	return __deflate_decompress(src, slen, dst, dlen, ctx);
 }

 static struct crypto_alg alg = {
 	.cra_name		= "deflate",
 	.cra_flags		= CRYPTO_ALG_TYPE_COMPRESS,
 	.cra_ctxsize		= sizeof(struct deflate_ctx),
 	.cra_module		= THIS_MODULE,
 	.cra_init		= deflate_init,
 	.cra_exit		= deflate_exit,
 	.cra_u			= { .compress = {
 	.coa_compress 		= deflate_compress,
 	.coa_decompress  	= deflate_decompress } }
 };

 static struct scomp_alg scomp[] = { {
 	.alloc_ctx		= deflate_alloc_ctx,
 	.free_ctx		= deflate_free_ctx,
 	.compress		= deflate_scompress,
 	.decompress		= deflate_sdecompress,
 	.base			= {
 		.cra_name	= "deflate",
 		.cra_driver_name = "deflate-scomp",
 		.cra_module	 = THIS_MODULE,
 	}
 }, {
 	.alloc_ctx		= zlib_deflate_alloc_ctx,
 	.free_ctx		= deflate_free_ctx,
 	.compress		= deflate_scompress,
 	.decompress		= deflate_sdecompress,
 	.base			= {
 		.cra_name	= "zlib-deflate",
 		.cra_driver_name = "zlib-deflate-scomp",
 		.cra_module	 = THIS_MODULE,
 	}
 } };

 static int __init deflate_mod_init(void)
 {
 	int ret;

 	ret = crypto_register_alg(&alg);
 	if (ret)
 		return ret;

 	ret = crypto_register_scomps(scomp, ARRAY_SIZE(scomp));
 	if (ret) {
 		crypto_unregister_alg(&alg);
 		return ret;
 	}

 	return ret;
 }

 static void __exit deflate_mod_fini(void)
 {
 	crypto_unregister_alg(&alg);
 	crypto_unregister_scomps(scomp, ARRAY_SIZE(scomp));
 }

 subsys_initcall(deflate_mod_init);
 module_exit(deflate_mod_fini);

 MODULE_LICENSE("GPL");
 MODULE_DESCRIPTION("Deflate Compression Algorithm for IPCOMP");
 MODULE_AUTHOR("James Morris <jmorris@intercode.com.au>");
 MODULE_ALIAS_CRYPTO("deflate");
	/*
	* Cryptographic API.
	*
	* Deflate algorithm (RFC 1951), implemented here primarily for use
	* by IPCOMP (RFC 3173 & RFC 2394).
	*
	* Copyright (c) 2003 James Morris <jmorris@intercode.com.au>
	*
	* 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.
	*
	* The default winbits of 11 should suit most packets, and it may be something
	* to configure on a per-tfm basis in the future.
	*
	* Currently, compression history is not maintained between tfm calls, as
	* it is not needed for IPCOMP and keeps the code simpler. It can be
	* implemented if someone wants it.
	*/
	#include <linux/init.h>
	#include <linux/module.h>
	#include <linux/crypto.h>
	#include <linux/zlib.h>
	#include <linux/vmalloc.h>
	#include <linux/interrupt.h>
	#include <linux/mm.h>
	#include <linux/net.h>
	#include <crypto/internal/scompress.h>

	#define DEFLATE_DEF_LEVEL Z_DEFAULT_COMPRESSION
	#define DEFLATE_DEF_WINBITS 11
	#define DEFLATE_DEF_MEMLEVEL MAX_MEM_LEVEL

	struct deflate_ctx {
	struct z_stream_s comp_stream;
	struct z_stream_s decomp_stream;
	};

	static int deflate_comp_init(struct deflate_ctx *ctx, int format)
	{
	int ret = 0;
	struct z_stream_s *stream = &ctx->comp_stream;

	stream->workspace = vzalloc(zlib_deflate_workspacesize(
	MAX_WBITS, MAX_MEM_LEVEL));
	if (!stream->workspace) {
	ret = -ENOMEM;
	goto out;
	}
	if (format)
	ret = zlib_deflateInit(stream, 3);
	else
	ret = zlib_deflateInit2(stream, DEFLATE_DEF_LEVEL, Z_DEFLATED,
	-DEFLATE_DEF_WINBITS,
	DEFLATE_DEF_MEMLEVEL,
	Z_DEFAULT_STRATEGY);
	if (ret != Z_OK) {
	ret = -EINVAL;
	goto out_free;
	}
	out:
	return ret;
	out_free:
	vfree(stream->workspace);
	goto out;
	}

	static int deflate_decomp_init(struct deflate_ctx *ctx, int format)
	{
	int ret = 0;
	struct z_stream_s *stream = &ctx->decomp_stream;

	stream->workspace = vzalloc(zlib_inflate_workspacesize());
	if (!stream->workspace) {
	ret = -ENOMEM;
	goto out;
	}
	if (format)
	ret = zlib_inflateInit(stream);
	else
	ret = zlib_inflateInit2(stream, -DEFLATE_DEF_WINBITS);
	if (ret != Z_OK) {
	ret = -EINVAL;
	goto out_free;
	}
	out:
	return ret;
	out_free:
	vfree(stream->workspace);
	goto out;
	}

	static void deflate_comp_exit(struct deflate_ctx *ctx)
	{
	zlib_deflateEnd(&ctx->comp_stream);
	vfree(ctx->comp_stream.workspace);
	}

	static void deflate_decomp_exit(struct deflate_ctx *ctx)
	{
	zlib_inflateEnd(&ctx->decomp_stream);
	vfree(ctx->decomp_stream.workspace);
	}

	static int __deflate_init(void *ctx, int format)
	{
	int ret;

	ret = deflate_comp_init(ctx, format);
	if (ret)
	goto out;
	ret = deflate_decomp_init(ctx, format);
	if (ret)
	deflate_comp_exit(ctx);
	out:
	return ret;
	}

	static void gen_deflate_alloc_ctx(struct crypto_scomp tfm, int format)
	{
	struct deflate_ctx *ctx;
	int ret;

	ctx = kzalloc(sizeof(*ctx), GFP_KERNEL);
	if (!ctx)
	return ERR_PTR(-ENOMEM);

	ret = __deflate_init(ctx, format);
	if (ret) {
	kfree(ctx);
	return ERR_PTR(ret);
	}

	return ctx;
	}

	static void deflate_alloc_ctx(struct crypto_scomp tfm)
	{
	return gen_deflate_alloc_ctx(tfm, 0);
	}

	static void zlib_deflate_alloc_ctx(struct crypto_scomp tfm)
	{
	return gen_deflate_alloc_ctx(tfm, 1);
	}

	static int deflate_init(struct crypto_tfm *tfm)
	{
	struct deflate_ctx *ctx = crypto_tfm_ctx(tfm);

	return __deflate_init(ctx, 0);
	}

	static void __deflate_exit(void *ctx)
	{
	deflate_comp_exit(ctx);
	deflate_decomp_exit(ctx);
	}

	static void deflate_free_ctx(struct crypto_scomp tfm, void ctx)
	{
	__deflate_exit(ctx);
	kzfree(ctx);
	}

	static void deflate_exit(struct crypto_tfm *tfm)
	{
	struct deflate_ctx *ctx = crypto_tfm_ctx(tfm);

	__deflate_exit(ctx);
	}

	static int __deflate_compress(const u8 *src, unsigned int slen,
	u8 dst, unsigned int dlen, void *ctx)
	{
	int ret = 0;
	struct deflate_ctx *dctx = ctx;
	struct z_stream_s *stream = &dctx->comp_stream;

	ret = zlib_deflateReset(stream);
	if (ret != Z_OK) {
	ret = -EINVAL;
	goto out;
	}

	stream->next_in = (u8 *)src;
	stream->avail_in = slen;
	stream->next_out = (u8 *)dst;
	stream->avail_out = *dlen;

	ret = zlib_deflate(stream, Z_FINISH);
	if (ret != Z_STREAM_END) {
	ret = -EINVAL;
	goto out;
	}
	ret = 0;
	*dlen = stream->total_out;
	out:
	return ret;
	}

	static int deflate_compress(struct crypto_tfm tfm, const u8 src,
	unsigned int slen, u8 dst, unsigned int dlen)
	{
	struct deflate_ctx *dctx = crypto_tfm_ctx(tfm);

	return __deflate_compress(src, slen, dst, dlen, dctx);
	}

	static int deflate_scompress(struct crypto_scomp tfm, const u8 src,
	unsigned int slen, u8 dst, unsigned int dlen,
	void *ctx)
	{
	return __deflate_compress(src, slen, dst, dlen, ctx);
	}

	static int __deflate_decompress(const u8 *src, unsigned int slen,
	u8 dst, unsigned int dlen, void *ctx)
	{

	int ret = 0;
	struct deflate_ctx *dctx = ctx;
	struct z_stream_s *stream = &dctx->decomp_stream;

	ret = zlib_inflateReset(stream);
	if (ret != Z_OK) {
	ret = -EINVAL;
	goto out;
	}

	stream->next_in = (u8 *)src;
	stream->avail_in = slen;
	stream->next_out = (u8 *)dst;
	stream->avail_out = *dlen;

	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) {
	u8 zerostuff = 0;
	stream->next_in = &zerostuff;
	stream->avail_in = 1;
	ret = zlib_inflate(stream, Z_FINISH);
	}
	if (ret != Z_STREAM_END) {
	ret = -EINVAL;
	goto out;
	}
	ret = 0;
	*dlen = stream->total_out;
	out:
	return ret;
	}

	static int deflate_decompress(struct crypto_tfm tfm, const u8 src,
	unsigned int slen, u8 dst, unsigned int dlen)
	{
	struct deflate_ctx *dctx = crypto_tfm_ctx(tfm);

	return __deflate_decompress(src, slen, dst, dlen, dctx);
	}

	static int deflate_sdecompress(struct crypto_scomp tfm, const u8 src,
	unsigned int slen, u8 dst, unsigned int dlen,
	void *ctx)
	{
	return __deflate_decompress(src, slen, dst, dlen, ctx);
	}

	static struct crypto_alg alg = {
	.cra_name = "deflate",
	.cra_flags = CRYPTO_ALG_TYPE_COMPRESS,
	.cra_ctxsize = sizeof(struct deflate_ctx),
	.cra_module = THIS_MODULE,
	.cra_init = deflate_init,
	.cra_exit = deflate_exit,
	.cra_u = { .compress = {
	.coa_compress = deflate_compress,
	.coa_decompress = deflate_decompress } }
	};

	static struct scomp_alg scomp[] = { {
	.alloc_ctx = deflate_alloc_ctx,
	.free_ctx = deflate_free_ctx,
	.compress = deflate_scompress,
	.decompress = deflate_sdecompress,
	.base = {
	.cra_name = "deflate",
	.cra_driver_name = "deflate-scomp",
	.cra_module = THIS_MODULE,
	}
	}, {
	.alloc_ctx = zlib_deflate_alloc_ctx,
	.free_ctx = deflate_free_ctx,
	.compress = deflate_scompress,
	.decompress = deflate_sdecompress,
	.base = {
	.cra_name = "zlib-deflate",
	.cra_driver_name = "zlib-deflate-scomp",
	.cra_module = THIS_MODULE,
	}
	} };

	static int __init deflate_mod_init(void)
	{
	int ret;

	ret = crypto_register_alg(&alg);
	if (ret)
	return ret;

	ret = crypto_register_scomps(scomp, ARRAY_SIZE(scomp));
	if (ret) {
	crypto_unregister_alg(&alg);
	return ret;
	}

	return ret;
	}

	static void __exit deflate_mod_fini(void)
	{
	crypto_unregister_alg(&alg);
	crypto_unregister_scomps(scomp, ARRAY_SIZE(scomp));
	}

	subsys_initcall(deflate_mod_init);
	module_exit(deflate_mod_fini);

	MODULE_LICENSE("GPL");
	MODULE_DESCRIPTION("Deflate Compression Algorithm for IPCOMP");
	MODULE_AUTHOR("James Morris <jmorris@intercode.com.au>");
	MODULE_ALIAS_CRYPTO("deflate");