[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 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));
}

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
a368f43d	46	static int deflate_comp_init(struct deflate_ctx *ctx, int format)
1da177e4 LT	47	{
	48	int ret = 0;
	49	struct z_stream_s *stream = &ctx->comp_stream;
	50
565d76cb	51	stream->workspace = vzalloc(zlib_deflate_workspacesize(
a368f43d	52	MAX_WBITS, MAX_MEM_LEVEL));
9472d763	53	if (!stream->workspace) {
1da177e4 LT	54	ret = -ENOMEM;
	55	goto out;
	56	}
a368f43d GC	57	if (format)
	58	ret = zlib_deflateInit(stream, 3);
	59	else
	60	ret = zlib_deflateInit2(stream, DEFLATE_DEF_LEVEL, Z_DEFLATED,
	61	-DEFLATE_DEF_WINBITS,
	62	DEFLATE_DEF_MEMLEVEL,
	63	Z_DEFAULT_STRATEGY);
1da177e4 LT	64	if (ret != Z_OK) {
	65	ret = -EINVAL;
	66	goto out_free;
	67	}
9472d763	68	out:
1da177e4 LT	69	return ret;
	70	out_free:
	71	vfree(stream->workspace);
	72	goto out;
	73	}
	74
a368f43d	75	static int deflate_decomp_init(struct deflate_ctx *ctx, int format)
1da177e4 LT	76	{
	77	int ret = 0;
	78	struct z_stream_s *stream = &ctx->decomp_stream;
	79
7ab24bfd	80	stream->workspace = vzalloc(zlib_inflate_workspacesize());
9472d763	81	if (!stream->workspace) {
1da177e4 LT	82	ret = -ENOMEM;
	83	goto out;
	84	}
a368f43d GC	85	if (format)
	86	ret = zlib_inflateInit(stream);
	87	else
	88	ret = zlib_inflateInit2(stream, -DEFLATE_DEF_WINBITS);
1da177e4 LT	89	if (ret != Z_OK) {
	90	ret = -EINVAL;
	91	goto out_free;
	92	}
	93	out:
	94	return ret;
	95	out_free:
7ab24bfd	96	vfree(stream->workspace);
1da177e4 LT	97	goto out;
	98	}
	99
	100	static void deflate_comp_exit(struct deflate_ctx *ctx)
	101	{
9ffb7146	102	zlib_deflateEnd(&ctx->comp_stream);
1da177e4 LT	103	vfree(ctx->comp_stream.workspace);
	104	}
	105
	106	static void deflate_decomp_exit(struct deflate_ctx *ctx)
	107	{
9ffb7146	108	zlib_inflateEnd(&ctx->decomp_stream);
7ab24bfd	109	vfree(ctx->decomp_stream.workspace);
1da177e4 LT	110	}
1da177e4 LT	111
a368f43d	112	static int __deflate_init(void *ctx, int format)
1da177e4 LT	113	{
1da177e4 LT	114	int ret;
9472d763	115
a368f43d	116	ret = deflate_comp_init(ctx, format);
1da177e4 LT	117	if (ret)
1da177e4 LT	118	goto out;
a368f43d	119	ret = deflate_decomp_init(ctx, format);
1da177e4 LT	120	if (ret)
	121	deflate_comp_exit(ctx);
	122	out:
	123	return ret;
	124	}
	125
a368f43d	126	static void gen_deflate_alloc_ctx(struct crypto_scomp tfm, int format)
f6ded09d GC	127	{
	128	struct deflate_ctx *ctx;
	129	int ret;
	130
	131	ctx = kzalloc(sizeof(*ctx), GFP_KERNEL);
	132	if (!ctx)
	133	return ERR_PTR(-ENOMEM);
	134
a368f43d	135	ret = __deflate_init(ctx, format);
f6ded09d GC	136	if (ret) {
	137	kfree(ctx);
	138	return ERR_PTR(ret);
	139	}
	140
	141	return ctx;
	142	}
	143
a368f43d GC	144	static void deflate_alloc_ctx(struct crypto_scomp tfm)
	145	{
	146	return gen_deflate_alloc_ctx(tfm, 0);
	147	}
	148
	149	static void zlib_deflate_alloc_ctx(struct crypto_scomp tfm)
	150	{
	151	return gen_deflate_alloc_ctx(tfm, 1);
	152	}
	153
f6ded09d	154	static int deflate_init(struct crypto_tfm *tfm)
1da177e4	155	{
6c2bb98b HX	156	struct deflate_ctx *ctx = crypto_tfm_ctx(tfm);
6c2bb98b HX	157
a368f43d	158	return __deflate_init(ctx, 0);
f6ded09d GC	159	}
	160
	161	static void __deflate_exit(void *ctx)
	162	{
1da177e4 LT	163	deflate_comp_exit(ctx);
	164	deflate_decomp_exit(ctx);
	165	}
	166
f6ded09d GC	167	static void deflate_free_ctx(struct crypto_scomp tfm, void ctx)
	168	{
	169	__deflate_exit(ctx);
	170	kzfree(ctx);
	171	}
	172
	173	static void deflate_exit(struct crypto_tfm *tfm)
	174	{
	175	struct deflate_ctx *ctx = crypto_tfm_ctx(tfm);
	176
	177	__deflate_exit(ctx);
	178	}
	179
	180	static int __deflate_compress(const u8 *src, unsigned int slen,
	181	u8 dst, unsigned int dlen, void *ctx)
1da177e4 LT	182	{
1da177e4 LT	183	int ret = 0;
f6ded09d	184	struct deflate_ctx *dctx = ctx;
1da177e4 LT	185	struct z_stream_s *stream = &dctx->comp_stream;
	186
	187	ret = zlib_deflateReset(stream);
	188	if (ret != Z_OK) {
	189	ret = -EINVAL;
	190	goto out;
	191	}
	192
	193	stream->next_in = (u8 *)src;
	194	stream->avail_in = slen;
	195	stream->next_out = (u8 *)dst;
	196	stream->avail_out = *dlen;
	197
	198	ret = zlib_deflate(stream, Z_FINISH);
	199	if (ret != Z_STREAM_END) {
	200	ret = -EINVAL;
	201	goto out;
	202	}
	203	ret = 0;
	204	*dlen = stream->total_out;
	205	out:
	206	return ret;
	207	}
9472d763	208
f6ded09d GC	209	static int deflate_compress(struct crypto_tfm tfm, const u8 src,
	210	unsigned int slen, u8 dst, unsigned int dlen)
	211	{
	212	struct deflate_ctx *dctx = crypto_tfm_ctx(tfm);
	213
	214	return __deflate_compress(src, slen, dst, dlen, dctx);
	215	}
	216
	217	static int deflate_scompress(struct crypto_scomp tfm, const u8 src,
	218	unsigned int slen, u8 dst, unsigned int dlen,
	219	void *ctx)
	220	{
	221	return __deflate_compress(src, slen, dst, dlen, ctx);
	222	}
	223
	224	static int __deflate_decompress(const u8 *src, unsigned int slen,
	225	u8 dst, unsigned int dlen, void *ctx)
1da177e4	226	{
9472d763	227
1da177e4	228	int ret = 0;
f6ded09d	229	struct deflate_ctx *dctx = ctx;
1da177e4 LT	230	struct z_stream_s *stream = &dctx->decomp_stream;
	231
	232	ret = zlib_inflateReset(stream);
	233	if (ret != Z_OK) {
	234	ret = -EINVAL;
	235	goto out;
	236	}
	237
	238	stream->next_in = (u8 *)src;
	239	stream->avail_in = slen;
	240	stream->next_out = (u8 *)dst;
	241	stream->avail_out = *dlen;
	242
	243	ret = zlib_inflate(stream, Z_SYNC_FLUSH);
	244	/*
	245	* Work around a bug in zlib, which sometimes wants to taste an extra
	246	* byte when being used in the (undocumented) raw deflate mode.
	247	* (From USAGI).
	248	*/
	249	if (ret == Z_OK && !stream->avail_in && stream->avail_out) {
	250	u8 zerostuff = 0;
	251	stream->next_in = &zerostuff;
9472d763	252	stream->avail_in = 1;
1da177e4 LT	253	ret = zlib_inflate(stream, Z_FINISH);
	254	}
	255	if (ret != Z_STREAM_END) {
	256	ret = -EINVAL;
	257	goto out;
	258	}
	259	ret = 0;
	260	*dlen = stream->total_out;
	261	out:
	262	return ret;
	263	}
	264
f6ded09d GC	265	static int deflate_decompress(struct crypto_tfm tfm, const u8 src,
	266	unsigned int slen, u8 dst, unsigned int dlen)
	267	{
	268	struct deflate_ctx *dctx = crypto_tfm_ctx(tfm);
	269
	270	return __deflate_decompress(src, slen, dst, dlen, dctx);
	271	}
	272
	273	static int deflate_sdecompress(struct crypto_scomp tfm, const u8 src,
	274	unsigned int slen, u8 dst, unsigned int dlen,
	275	void *ctx)
	276	{
	277	return __deflate_decompress(src, slen, dst, dlen, ctx);
	278	}
	279
1da177e4 LT	280	static struct crypto_alg alg = {
	281	.cra_name = "deflate",
	282	.cra_flags = CRYPTO_ALG_TYPE_COMPRESS,
	283	.cra_ctxsize = sizeof(struct deflate_ctx),
	284	.cra_module = THIS_MODULE,
c7fc0599 HX	285	.cra_init = deflate_init,
c7fc0599 HX	286	.cra_exit = deflate_exit,
1da177e4	287	.cra_u = { .compress = {
1da177e4 LT	288	.coa_compress = deflate_compress,
	289	.coa_decompress = deflate_decompress } }
	290	};
	291
a368f43d	292	static struct scomp_alg scomp[] = { {
f6ded09d GC	293	.alloc_ctx = deflate_alloc_ctx,
	294	.free_ctx = deflate_free_ctx,
	295	.compress = deflate_scompress,
	296	.decompress = deflate_sdecompress,
	297	.base = {
	298	.cra_name = "deflate",
	299	.cra_driver_name = "deflate-scomp",
	300	.cra_module = THIS_MODULE,
	301	}
a368f43d GC	302	}, {
	303	.alloc_ctx = zlib_deflate_alloc_ctx,
	304	.free_ctx = deflate_free_ctx,
	305	.compress = deflate_scompress,
	306	.decompress = deflate_sdecompress,
	307	.base = {
	308	.cra_name = "zlib-deflate",
	309	.cra_driver_name = "zlib-deflate-scomp",
	310	.cra_module = THIS_MODULE,
	311	}
	312	} };
f6ded09d	313
3af5b90b	314	static int __init deflate_mod_init(void)
1da177e4	315	{
f6ded09d GC	316	int ret;
	317
	318	ret = crypto_register_alg(&alg);
	319	if (ret)
	320	return ret;
	321
a368f43d	322	ret = crypto_register_scomps(scomp, ARRAY_SIZE(scomp));
f6ded09d GC	323	if (ret) {
	324	crypto_unregister_alg(&alg);
	325	return ret;
	326	}
	327
	328	return ret;
1da177e4 LT	329	}
1da177e4 LT	330
3af5b90b	331	static void __exit deflate_mod_fini(void)
1da177e4 LT	332	{
1da177e4 LT	333	crypto_unregister_alg(&alg);
a368f43d	334	crypto_unregister_scomps(scomp, ARRAY_SIZE(scomp));
1da177e4 LT	335	}
1da177e4 LT	336
3af5b90b KB	337	module_init(deflate_mod_init);
3af5b90b KB	338	module_exit(deflate_mod_fini);
1da177e4 LT	339
	340	MODULE_LICENSE("GPL");
	341	MODULE_DESCRIPTION("Deflate Compression Algorithm for IPCOMP");
	342	MODULE_AUTHOR("James Morris <[email protected]>");
5d26a105	343	MODULE_ALIAS_CRYPTO("deflate");