[deliverable/linux.git] / crypto / deflate.c

/*
 * 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>

#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 ret = 0;
	struct z_stream_s *stream = &ctx->comp_stream;

	stream->workspace = vzalloc(zlib_deflate_workspacesize(
				-DEFLATE_DEF_WINBITS, DEFLATE_DEF_MEMLEVEL));
	if (!stream->workspace) {
		ret = -ENOMEM;
		goto out;
	}
	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 ret = 0;
	struct z_stream_s *stream = &ctx->decomp_stream;

	stream->workspace = vzalloc(zlib_inflate_workspacesize());
	if (!stream->workspace) {
		ret = -ENOMEM;
		goto out;
	}
	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(struct crypto_tfm *tfm)
{
	struct deflate_ctx *ctx = crypto_tfm_ctx(tfm);
	int ret;

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

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

	deflate_comp_exit(ctx);
	deflate_decomp_exit(ctx);
}

static int deflate_compress(struct crypto_tfm *tfm, const u8 *src,
			    unsigned int slen, u8 *dst, unsigned int *dlen)
{
	int ret = 0;
	struct deflate_ctx *dctx = crypto_tfm_ctx(tfm);
	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_decompress(struct crypto_tfm *tfm, const u8 *src,
			      unsigned int slen, u8 *dst, unsigned int *dlen)
{

	int ret = 0;
	struct deflate_ctx *dctx = crypto_tfm_ctx(tfm);
	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 struct crypto_alg alg = {
	.cra_name		= "deflate",
	.cra_flags		= CRYPTO_ALG_TYPE_COMPRESS,
	.cra_ctxsize		= sizeof(struct deflate_ctx),
	.cra_module		= THIS_MODULE,
	.cra_list		= LIST_HEAD_INIT(alg.cra_list),
	.cra_init		= deflate_init,
	.cra_exit		= deflate_exit,
	.cra_u			= { .compress = {
	.coa_compress 		= deflate_compress,
	.coa_decompress  	= deflate_decompress } }
};

static int __init deflate_mod_init(void)
{
	return crypto_register_alg(&alg);
}

static void __exit deflate_mod_fini(void)
{
	crypto_unregister_alg(&alg);
}

module_init(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>");
Commit	Line	Data
9472d763	1	/*
1da177e4 LT	2	* Cryptographic API.
	3	*
	4	* Deflate algorithm (RFC 1951), implemented here primarily for use
	5	* by IPCOMP (RFC 3173 & RFC 2394).
	6	*
	7	* Copyright (c) 2003 James Morris <jmorris@intercode.com.au>
9472d763	8	*
1da177e4 LT	9	* This program is free software; you can redistribute it and/or modify it
1da177e4 LT	10	* under the terms of the GNU General Public License as published by the Free
9472d763	11	* Software Foundation; either version 2 of the License, or (at your option)
1da177e4 LT	12	* any later version.
	13	*
	14	* FIXME: deflate transforms will require up to a total of about 436k of kernel
	15	* memory on i386 (390k for compression, the rest for decompression), as the
	16	* current zlib kernel code uses a worst case pre-allocation system by default.
	17	* This needs to be fixed so that the amount of memory required is properly
	18	* related to the winbits and memlevel parameters.
	19	*
	20	* The default winbits of 11 should suit most packets, and it may be something
	21	* to configure on a per-tfm basis in the future.
	22	*
	23	* Currently, compression history is not maintained between tfm calls, as
	24	* it is not needed for IPCOMP and keeps the code simpler. It can be
	25	* implemented if someone wants it.
	26	*/
	27	#include <linux/init.h>
	28	#include <linux/module.h>
	29	#include <linux/crypto.h>
	30	#include <linux/zlib.h>
	31	#include <linux/vmalloc.h>
	32	#include <linux/interrupt.h>
	33	#include <linux/mm.h>
	34	#include <linux/net.h>
1da177e4 LT	35
	36	#define DEFLATE_DEF_LEVEL Z_DEFAULT_COMPRESSION
	37	#define DEFLATE_DEF_WINBITS 11
	38	#define DEFLATE_DEF_MEMLEVEL MAX_MEM_LEVEL
	39
	40	struct deflate_ctx {
	41	struct z_stream_s comp_stream;
	42	struct z_stream_s decomp_stream;
	43	};
	44
	45	static int deflate_comp_init(struct deflate_ctx *ctx)
	46	{
	47	int ret = 0;
	48	struct z_stream_s *stream = &ctx->comp_stream;
	49
565d76cb JK	50	stream->workspace = vzalloc(zlib_deflate_workspacesize(
565d76cb JK	51	-DEFLATE_DEF_WINBITS, DEFLATE_DEF_MEMLEVEL));
9472d763	52	if (!stream->workspace) {
1da177e4 LT	53	ret = -ENOMEM;
	54	goto out;
	55	}
1da177e4 LT	56	ret = zlib_deflateInit2(stream, DEFLATE_DEF_LEVEL, Z_DEFLATED,
	57	-DEFLATE_DEF_WINBITS, DEFLATE_DEF_MEMLEVEL,
	58	Z_DEFAULT_STRATEGY);
	59	if (ret != Z_OK) {
	60	ret = -EINVAL;
	61	goto out_free;
	62	}
9472d763	63	out:
1da177e4 LT	64	return ret;
	65	out_free:
	66	vfree(stream->workspace);
	67	goto out;
	68	}
	69
	70	static int deflate_decomp_init(struct deflate_ctx *ctx)
	71	{
	72	int ret = 0;
	73	struct z_stream_s *stream = &ctx->decomp_stream;
	74
7ab24bfd	75	stream->workspace = vzalloc(zlib_inflate_workspacesize());
9472d763	76	if (!stream->workspace) {
1da177e4 LT	77	ret = -ENOMEM;
	78	goto out;
	79	}
1da177e4 LT	80	ret = zlib_inflateInit2(stream, -DEFLATE_DEF_WINBITS);
	81	if (ret != Z_OK) {
	82	ret = -EINVAL;
	83	goto out_free;
	84	}
	85	out:
	86	return ret;
	87	out_free:
7ab24bfd	88	vfree(stream->workspace);
1da177e4 LT	89	goto out;
	90	}
	91
	92	static void deflate_comp_exit(struct deflate_ctx *ctx)
	93	{
9ffb7146	94	zlib_deflateEnd(&ctx->comp_stream);
1da177e4 LT	95	vfree(ctx->comp_stream.workspace);
	96	}
	97
	98	static void deflate_decomp_exit(struct deflate_ctx *ctx)
	99	{
9ffb7146	100	zlib_inflateEnd(&ctx->decomp_stream);
7ab24bfd	101	vfree(ctx->decomp_stream.workspace);
1da177e4 LT	102	}
1da177e4 LT	103
6c2bb98b	104	static int deflate_init(struct crypto_tfm *tfm)
1da177e4	105	{
6c2bb98b	106	struct deflate_ctx *ctx = crypto_tfm_ctx(tfm);
1da177e4	107	int ret;
9472d763	108
1da177e4 LT	109	ret = deflate_comp_init(ctx);
	110	if (ret)
	111	goto out;
	112	ret = deflate_decomp_init(ctx);
	113	if (ret)
	114	deflate_comp_exit(ctx);
	115	out:
	116	return ret;
	117	}
	118
6c2bb98b	119	static void deflate_exit(struct crypto_tfm *tfm)
1da177e4	120	{
6c2bb98b HX	121	struct deflate_ctx *ctx = crypto_tfm_ctx(tfm);
6c2bb98b HX	122
1da177e4 LT	123	deflate_comp_exit(ctx);
	124	deflate_decomp_exit(ctx);
	125	}
	126
6c2bb98b HX	127	static int deflate_compress(struct crypto_tfm tfm, const u8 src,
6c2bb98b HX	128	unsigned int slen, u8 dst, unsigned int dlen)
1da177e4 LT	129	{
1da177e4 LT	130	int ret = 0;
6c2bb98b	131	struct deflate_ctx *dctx = crypto_tfm_ctx(tfm);
1da177e4 LT	132	struct z_stream_s *stream = &dctx->comp_stream;
	133
	134	ret = zlib_deflateReset(stream);
	135	if (ret != Z_OK) {
	136	ret = -EINVAL;
	137	goto out;
	138	}
	139
	140	stream->next_in = (u8 *)src;
	141	stream->avail_in = slen;
	142	stream->next_out = (u8 *)dst;
	143	stream->avail_out = *dlen;
	144
	145	ret = zlib_deflate(stream, Z_FINISH);
	146	if (ret != Z_STREAM_END) {
	147	ret = -EINVAL;
	148	goto out;
	149	}
	150	ret = 0;
	151	*dlen = stream->total_out;
	152	out:
	153	return ret;
	154	}
9472d763	155
6c2bb98b HX	156	static int deflate_decompress(struct crypto_tfm tfm, const u8 src,
6c2bb98b HX	157	unsigned int slen, u8 dst, unsigned int dlen)
1da177e4	158	{
9472d763	159
1da177e4	160	int ret = 0;
6c2bb98b	161	struct deflate_ctx *dctx = crypto_tfm_ctx(tfm);
1da177e4 LT	162	struct z_stream_s *stream = &dctx->decomp_stream;
	163
	164	ret = zlib_inflateReset(stream);
	165	if (ret != Z_OK) {
	166	ret = -EINVAL;
	167	goto out;
	168	}
	169
	170	stream->next_in = (u8 *)src;
	171	stream->avail_in = slen;
	172	stream->next_out = (u8 *)dst;
	173	stream->avail_out = *dlen;
	174
	175	ret = zlib_inflate(stream, Z_SYNC_FLUSH);
	176	/*
	177	* Work around a bug in zlib, which sometimes wants to taste an extra
	178	* byte when being used in the (undocumented) raw deflate mode.
	179	* (From USAGI).
	180	*/
	181	if (ret == Z_OK && !stream->avail_in && stream->avail_out) {
	182	u8 zerostuff = 0;
	183	stream->next_in = &zerostuff;
9472d763	184	stream->avail_in = 1;
1da177e4 LT	185	ret = zlib_inflate(stream, Z_FINISH);
	186	}
	187	if (ret != Z_STREAM_END) {
	188	ret = -EINVAL;
	189	goto out;
	190	}
	191	ret = 0;
	192	*dlen = stream->total_out;
	193	out:
	194	return ret;
	195	}
	196
	197	static struct crypto_alg alg = {
	198	.cra_name = "deflate",
	199	.cra_flags = CRYPTO_ALG_TYPE_COMPRESS,
	200	.cra_ctxsize = sizeof(struct deflate_ctx),
	201	.cra_module = THIS_MODULE,
	202	.cra_list = LIST_HEAD_INIT(alg.cra_list),
c7fc0599 HX	203	.cra_init = deflate_init,
c7fc0599 HX	204	.cra_exit = deflate_exit,
1da177e4	205	.cra_u = { .compress = {
1da177e4 LT	206	.coa_compress = deflate_compress,
	207	.coa_decompress = deflate_decompress } }
	208	};
	209
3af5b90b	210	static int __init deflate_mod_init(void)
1da177e4 LT	211	{
	212	return crypto_register_alg(&alg);
	213	}
	214
3af5b90b	215	static void __exit deflate_mod_fini(void)
1da177e4 LT	216	{
	217	crypto_unregister_alg(&alg);
	218	}
	219
3af5b90b KB	220	module_init(deflate_mod_init);
3af5b90b KB	221	module_exit(deflate_mod_fini);
1da177e4 LT	222
	223	MODULE_LICENSE("GPL");
	224	MODULE_DESCRIPTION("Deflate Compression Algorithm for IPCOMP");
	225	MODULE_AUTHOR("James Morris <jmorris@intercode.com.au>");
	226