[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 <[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.
 *
 * 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 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(void *ctx)
{
	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_alloc_ctx(struct crypto_scomp *tfm)
{
	struct deflate_ctx *ctx;
	int ret;

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

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

	return ctx;
}

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

	return __deflate_init(ctx);
}

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,
	}
};

static int __init deflate_mod_init(void)
{
	int ret;

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

	ret = crypto_register_scomp(&scomp);
	if (ret) {
		crypto_unregister_alg(&alg);
		return ret;
	}

	return ret;
}

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

module_init(deflate_mod_init);
module_exit(deflate_mod_fini);

MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("Deflate Compression Algorithm for IPCOMP");
MODULE_AUTHOR("James Morris <[email protected]>");
MODULE_ALIAS_CRYPTO("deflate");
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 <[email protected]>
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>
f6ded09d	35	#include <crypto/internal/scompress.h>
1da177e4 LT	36
	37	#define DEFLATE_DEF_LEVEL Z_DEFAULT_COMPRESSION
	38	#define DEFLATE_DEF_WINBITS 11
	39	#define DEFLATE_DEF_MEMLEVEL MAX_MEM_LEVEL
	40
	41	struct deflate_ctx {
	42	struct z_stream_s comp_stream;
	43	struct z_stream_s decomp_stream;
	44	};
	45
	46	static int deflate_comp_init(struct deflate_ctx *ctx)
	47	{
	48	int ret = 0;
	49	struct z_stream_s *stream = &ctx->comp_stream;
	50
565d76cb JK	51	stream->workspace = vzalloc(zlib_deflate_workspacesize(
565d76cb JK	52	-DEFLATE_DEF_WINBITS, DEFLATE_DEF_MEMLEVEL));
9472d763	53	if (!stream->workspace) {
1da177e4 LT	54	ret = -ENOMEM;
	55	goto out;
	56	}
1da177e4 LT	57	ret = zlib_deflateInit2(stream, DEFLATE_DEF_LEVEL, Z_DEFLATED,
	58	-DEFLATE_DEF_WINBITS, DEFLATE_DEF_MEMLEVEL,
	59	Z_DEFAULT_STRATEGY);
	60	if (ret != Z_OK) {
	61	ret = -EINVAL;
	62	goto out_free;
	63	}
9472d763	64	out:
1da177e4 LT	65	return ret;
	66	out_free:
	67	vfree(stream->workspace);
	68	goto out;
	69	}
	70
	71	static int deflate_decomp_init(struct deflate_ctx *ctx)
	72	{
	73	int ret = 0;
	74	struct z_stream_s *stream = &ctx->decomp_stream;
	75
7ab24bfd	76	stream->workspace = vzalloc(zlib_inflate_workspacesize());
9472d763	77	if (!stream->workspace) {
1da177e4 LT	78	ret = -ENOMEM;
	79	goto out;
	80	}
1da177e4 LT	81	ret = zlib_inflateInit2(stream, -DEFLATE_DEF_WINBITS);
	82	if (ret != Z_OK) {
	83	ret = -EINVAL;
	84	goto out_free;
	85	}
	86	out:
	87	return ret;
	88	out_free:
7ab24bfd	89	vfree(stream->workspace);
1da177e4 LT	90	goto out;
	91	}
	92
	93	static void deflate_comp_exit(struct deflate_ctx *ctx)
	94	{
9ffb7146	95	zlib_deflateEnd(&ctx->comp_stream);
1da177e4 LT	96	vfree(ctx->comp_stream.workspace);
	97	}
	98
	99	static void deflate_decomp_exit(struct deflate_ctx *ctx)
	100	{
9ffb7146	101	zlib_inflateEnd(&ctx->decomp_stream);
7ab24bfd	102	vfree(ctx->decomp_stream.workspace);
1da177e4 LT	103	}
1da177e4 LT	104
f6ded09d	105	static int __deflate_init(void *ctx)
1da177e4 LT	106	{
1da177e4 LT	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
f6ded09d GC	119	static void deflate_alloc_ctx(struct crypto_scomp tfm)
	120	{
	121	struct deflate_ctx *ctx;
	122	int ret;
	123
	124	ctx = kzalloc(sizeof(*ctx), GFP_KERNEL);
	125	if (!ctx)
	126	return ERR_PTR(-ENOMEM);
	127
	128	ret = __deflate_init(ctx);
	129	if (ret) {
	130	kfree(ctx);
	131	return ERR_PTR(ret);
	132	}
	133
	134	return ctx;
	135	}
	136
	137	static int deflate_init(struct crypto_tfm *tfm)
1da177e4	138	{
6c2bb98b HX	139	struct deflate_ctx *ctx = crypto_tfm_ctx(tfm);
6c2bb98b HX	140
f6ded09d GC	141	return __deflate_init(ctx);
	142	}
	143
	144	static void __deflate_exit(void *ctx)
	145	{
1da177e4 LT	146	deflate_comp_exit(ctx);
	147	deflate_decomp_exit(ctx);
	148	}
	149
f6ded09d GC	150	static void deflate_free_ctx(struct crypto_scomp tfm, void ctx)
	151	{
	152	__deflate_exit(ctx);
	153	kzfree(ctx);
	154	}
	155
	156	static void deflate_exit(struct crypto_tfm *tfm)
	157	{
	158	struct deflate_ctx *ctx = crypto_tfm_ctx(tfm);
	159
	160	__deflate_exit(ctx);
	161	}
	162
	163	static int __deflate_compress(const u8 *src, unsigned int slen,
	164	u8 dst, unsigned int dlen, void *ctx)
1da177e4 LT	165	{
1da177e4 LT	166	int ret = 0;
f6ded09d	167	struct deflate_ctx *dctx = ctx;
1da177e4 LT	168	struct z_stream_s *stream = &dctx->comp_stream;
	169
	170	ret = zlib_deflateReset(stream);
	171	if (ret != Z_OK) {
	172	ret = -EINVAL;
	173	goto out;
	174	}
	175
	176	stream->next_in = (u8 *)src;
	177	stream->avail_in = slen;
	178	stream->next_out = (u8 *)dst;
	179	stream->avail_out = *dlen;
	180
	181	ret = zlib_deflate(stream, Z_FINISH);
	182	if (ret != Z_STREAM_END) {
	183	ret = -EINVAL;
	184	goto out;
	185	}
	186	ret = 0;
	187	*dlen = stream->total_out;
	188	out:
	189	return ret;
	190	}
9472d763	191
f6ded09d GC	192	static int deflate_compress(struct crypto_tfm tfm, const u8 src,
	193	unsigned int slen, u8 dst, unsigned int dlen)
	194	{
	195	struct deflate_ctx *dctx = crypto_tfm_ctx(tfm);
	196
	197	return __deflate_compress(src, slen, dst, dlen, dctx);
	198	}
	199
	200	static int deflate_scompress(struct crypto_scomp tfm, const u8 src,
	201	unsigned int slen, u8 dst, unsigned int dlen,
	202	void *ctx)
	203	{
	204	return __deflate_compress(src, slen, dst, dlen, ctx);
	205	}
	206
	207	static int __deflate_decompress(const u8 *src, unsigned int slen,
	208	u8 dst, unsigned int dlen, void *ctx)
1da177e4	209	{
9472d763	210
1da177e4	211	int ret = 0;
f6ded09d	212	struct deflate_ctx *dctx = ctx;
1da177e4 LT	213	struct z_stream_s *stream = &dctx->decomp_stream;
	214
	215	ret = zlib_inflateReset(stream);
	216	if (ret != Z_OK) {
	217	ret = -EINVAL;
	218	goto out;
	219	}
	220
	221	stream->next_in = (u8 *)src;
	222	stream->avail_in = slen;
	223	stream->next_out = (u8 *)dst;
	224	stream->avail_out = *dlen;
	225
	226	ret = zlib_inflate(stream, Z_SYNC_FLUSH);
	227	/*
	228	* Work around a bug in zlib, which sometimes wants to taste an extra
	229	* byte when being used in the (undocumented) raw deflate mode.
	230	* (From USAGI).
	231	*/
	232	if (ret == Z_OK && !stream->avail_in && stream->avail_out) {
	233	u8 zerostuff = 0;
	234	stream->next_in = &zerostuff;
9472d763	235	stream->avail_in = 1;
1da177e4 LT	236	ret = zlib_inflate(stream, Z_FINISH);
	237	}
	238	if (ret != Z_STREAM_END) {
	239	ret = -EINVAL;
	240	goto out;
	241	}
	242	ret = 0;
	243	*dlen = stream->total_out;
	244	out:
	245	return ret;
	246	}
	247
f6ded09d GC	248	static int deflate_decompress(struct crypto_tfm tfm, const u8 src,
	249	unsigned int slen, u8 dst, unsigned int dlen)
	250	{
	251	struct deflate_ctx *dctx = crypto_tfm_ctx(tfm);
	252
	253	return __deflate_decompress(src, slen, dst, dlen, dctx);
	254	}
	255
	256	static int deflate_sdecompress(struct crypto_scomp tfm, const u8 src,
	257	unsigned int slen, u8 dst, unsigned int dlen,
	258	void *ctx)
	259	{
	260	return __deflate_decompress(src, slen, dst, dlen, ctx);
	261	}
	262
1da177e4 LT	263	static struct crypto_alg alg = {
	264	.cra_name = "deflate",
	265	.cra_flags = CRYPTO_ALG_TYPE_COMPRESS,
	266	.cra_ctxsize = sizeof(struct deflate_ctx),
	267	.cra_module = THIS_MODULE,
c7fc0599 HX	268	.cra_init = deflate_init,
c7fc0599 HX	269	.cra_exit = deflate_exit,
1da177e4	270	.cra_u = { .compress = {
1da177e4 LT	271	.coa_compress = deflate_compress,
	272	.coa_decompress = deflate_decompress } }
	273	};
	274
f6ded09d GC	275	static struct scomp_alg scomp = {
	276	.alloc_ctx = deflate_alloc_ctx,
	277	.free_ctx = deflate_free_ctx,
	278	.compress = deflate_scompress,
	279	.decompress = deflate_sdecompress,
	280	.base = {
	281	.cra_name = "deflate",
	282	.cra_driver_name = "deflate-scomp",
	283	.cra_module = THIS_MODULE,
	284	}
	285	};
	286
3af5b90b	287	static int __init deflate_mod_init(void)
1da177e4	288	{
f6ded09d GC	289	int ret;
	290
	291	ret = crypto_register_alg(&alg);
	292	if (ret)
	293	return ret;
	294
	295	ret = crypto_register_scomp(&scomp);
	296	if (ret) {
	297	crypto_unregister_alg(&alg);
	298	return ret;
	299	}
	300
	301	return ret;
1da177e4 LT	302	}
1da177e4 LT	303
3af5b90b	304	static void __exit deflate_mod_fini(void)
1da177e4 LT	305	{
1da177e4 LT	306	crypto_unregister_alg(&alg);
f6ded09d	307	crypto_unregister_scomp(&scomp);
1da177e4 LT	308	}
1da177e4 LT	309
3af5b90b KB	310	module_init(deflate_mod_init);
3af5b90b KB	311	module_exit(deflate_mod_fini);
1da177e4 LT	312
	313	MODULE_LICENSE("GPL");
	314	MODULE_DESCRIPTION("Deflate Compression Algorithm for IPCOMP");
	315	MODULE_AUTHOR("James Morris <[email protected]>");
5d26a105	316	MODULE_ALIAS_CRYPTO("deflate");