[GitHub/mt8127/android_kernel_alcatel_ttab.git] / crypto / zlib.c

/*
 * Cryptographic API.
 *
 * Zlib algorithm
 *
 * Copyright 2008 Sony Corporation
 *
 * Based on deflate.c, which is
 * 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.
 */

#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 <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);
		vfree(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];
	int window_bits, mem_level;
	size_t workspacesize;
	int ret;

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

	zlib_comp_exit(ctx);

	window_bits = tb[ZLIB_COMP_WINDOWBITS]
					? nla_get_u32(tb[ZLIB_COMP_WINDOWBITS])
					: MAX_WBITS;
	mem_level = tb[ZLIB_COMP_MEMLEVEL]
					? nla_get_u32(tb[ZLIB_COMP_MEMLEVEL])
					: DEF_MEM_LEVEL;

	workspacesize = zlib_deflate_workspacesize(window_bits, mem_level);
	stream->workspace = vzalloc(workspacesize);
	if (!stream->workspace)
		return -ENOMEM;

	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,
				window_bits,
				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 = vzalloc(zlib_inflate_workspacesize());
	if (!stream->workspace)
		return -ENOMEM;

	ret = zlib_inflateInit2(stream, ctx->decomp_windowBits);
	if (ret != Z_OK) {
		vfree(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");
MODULE_ALIAS_CRYPTO("zlib");
Commit	Line	Data
bf68e65e GU	1	/*
	2	* Cryptographic API.
	3	*
	4	* Zlib algorithm
	5	*
	6	* Copyright 2008 Sony Corporation
	7	*
	8	* Based on deflate.c, which is
	9	* Copyright (c) 2003 James Morris <jmorris@intercode.com.au>
	10	*
	11	* This program is free software; you can redistribute it and/or modify it
	12	* under the terms of the GNU General Public License as published by the Free
	13	* Software Foundation; either version 2 of the License, or (at your option)
	14	* any later version.
	15	*
	16	* FIXME: deflate transforms will require up to a total of about 436k of kernel
	17	* memory on i386 (390k for compression, the rest for decompression), as the
	18	* current zlib kernel code uses a worst case pre-allocation system by default.
	19	* This needs to be fixed so that the amount of memory required is properly
	20	* related to the winbits and memlevel parameters.
	21	*/
	22
	23	#define pr_fmt(fmt) "%s: " fmt, __func__
	24
	25	#include <linux/init.h>
	26	#include <linux/module.h>
	27	#include <linux/zlib.h>
	28	#include <linux/vmalloc.h>
	29	#include <linux/interrupt.h>
	30	#include <linux/mm.h>
	31	#include <linux/net.h>
bf68e65e GU	32
	33	#include <crypto/internal/compress.h>
	34
	35	#include <net/netlink.h>
	36
	37
	38	struct zlib_ctx {
	39	struct z_stream_s comp_stream;
	40	struct z_stream_s decomp_stream;
	41	int decomp_windowBits;
	42	};
	43
	44
	45	static void zlib_comp_exit(struct zlib_ctx *ctx)
	46	{
	47	struct z_stream_s *stream = &ctx->comp_stream;
	48
	49	if (stream->workspace) {
	50	zlib_deflateEnd(stream);
	51	vfree(stream->workspace);
	52	stream->workspace = NULL;
	53	}
	54	}
	55
	56	static void zlib_decomp_exit(struct zlib_ctx *ctx)
	57	{
	58	struct z_stream_s *stream = &ctx->decomp_stream;
	59
	60	if (stream->workspace) {
	61	zlib_inflateEnd(stream);
7ab24bfd	62	vfree(stream->workspace);
bf68e65e GU	63	stream->workspace = NULL;
	64	}
	65	}
	66
	67	static int zlib_init(struct crypto_tfm *tfm)
	68	{
	69	return 0;
	70	}
	71
	72	static void zlib_exit(struct crypto_tfm *tfm)
	73	{
	74	struct zlib_ctx *ctx = crypto_tfm_ctx(tfm);
	75
	76	zlib_comp_exit(ctx);
	77	zlib_decomp_exit(ctx);
	78	}
	79
	80
	81	static int zlib_compress_setup(struct crypto_pcomp tfm, void params,
	82	unsigned int len)
	83	{
	84	struct zlib_ctx *ctx = crypto_tfm_ctx(crypto_pcomp_tfm(tfm));
	85	struct z_stream_s *stream = &ctx->comp_stream;
	86	struct nlattr *tb[ZLIB_COMP_MAX + 1];
565d76cb	87	int window_bits, mem_level;
bf68e65e GU	88	size_t workspacesize;
	89	int ret;
	90
	91	ret = nla_parse(tb, ZLIB_COMP_MAX, params, len, NULL);
	92	if (ret)
	93	return ret;
	94
	95	zlib_comp_exit(ctx);
	96
565d76cb JK	97	window_bits = tb[ZLIB_COMP_WINDOWBITS]
	98	? nla_get_u32(tb[ZLIB_COMP_WINDOWBITS])
	99	: MAX_WBITS;
	100	mem_level = tb[ZLIB_COMP_MEMLEVEL]
	101	? nla_get_u32(tb[ZLIB_COMP_MEMLEVEL])
	102	: DEF_MEM_LEVEL;
	103
	104	workspacesize = zlib_deflate_workspacesize(window_bits, mem_level);
c8484594	105	stream->workspace = vzalloc(workspacesize);
bf68e65e GU	106	if (!stream->workspace)
	107	return -ENOMEM;
	108
bf68e65e GU	109	ret = zlib_deflateInit2(stream,
	110	tb[ZLIB_COMP_LEVEL]
	111	? nla_get_u32(tb[ZLIB_COMP_LEVEL])
	112	: Z_DEFAULT_COMPRESSION,
	113	tb[ZLIB_COMP_METHOD]
	114	? nla_get_u32(tb[ZLIB_COMP_METHOD])
	115	: Z_DEFLATED,
565d76cb JK	116	window_bits,
565d76cb JK	117	mem_level,
bf68e65e GU	118	tb[ZLIB_COMP_STRATEGY]
	119	? nla_get_u32(tb[ZLIB_COMP_STRATEGY])
	120	: Z_DEFAULT_STRATEGY);
	121	if (ret != Z_OK) {
	122	vfree(stream->workspace);
	123	stream->workspace = NULL;
	124	return -EINVAL;
	125	}
	126
	127	return 0;
	128	}
	129
	130	static int zlib_compress_init(struct crypto_pcomp *tfm)
	131	{
	132	int ret;
	133	struct zlib_ctx *dctx = crypto_tfm_ctx(crypto_pcomp_tfm(tfm));
	134	struct z_stream_s *stream = &dctx->comp_stream;
	135
	136	ret = zlib_deflateReset(stream);
	137	if (ret != Z_OK)
	138	return -EINVAL;
	139
	140	return 0;
	141	}
	142
	143	static int zlib_compress_update(struct crypto_pcomp *tfm,
	144	struct comp_request *req)
	145	{
	146	int ret;
	147	struct zlib_ctx *dctx = crypto_tfm_ctx(crypto_pcomp_tfm(tfm));
	148	struct z_stream_s *stream = &dctx->comp_stream;
	149
	150	pr_debug("avail_in %u, avail_out %u\n", req->avail_in, req->avail_out);
	151	stream->next_in = req->next_in;
	152	stream->avail_in = req->avail_in;
	153	stream->next_out = req->next_out;
	154	stream->avail_out = req->avail_out;
	155
	156	ret = zlib_deflate(stream, Z_NO_FLUSH);
	157	switch (ret) {
	158	case Z_OK:
	159	break;
	160
	161	case Z_BUF_ERROR:
	162	pr_debug("zlib_deflate could not make progress\n");
	163	return -EAGAIN;
	164
	165	default:
	166	pr_debug("zlib_deflate failed %d\n", ret);
	167	return -EINVAL;
	168	}
	169
3ce858cb	170	ret = req->avail_out - stream->avail_out;
bf68e65e GU	171	pr_debug("avail_in %u, avail_out %u (consumed %u, produced %u)\n",
bf68e65e GU	172	stream->avail_in, stream->avail_out,
3ce858cb	173	req->avail_in - stream->avail_in, ret);
bf68e65e GU	174	req->next_in = stream->next_in;
	175	req->avail_in = stream->avail_in;
	176	req->next_out = stream->next_out;
	177	req->avail_out = stream->avail_out;
3ce858cb	178	return ret;
bf68e65e GU	179	}
	180
	181	static int zlib_compress_final(struct crypto_pcomp *tfm,
	182	struct comp_request *req)
	183	{
	184	int ret;
	185	struct zlib_ctx *dctx = crypto_tfm_ctx(crypto_pcomp_tfm(tfm));
	186	struct z_stream_s *stream = &dctx->comp_stream;
	187
	188	pr_debug("avail_in %u, avail_out %u\n", req->avail_in, req->avail_out);
	189	stream->next_in = req->next_in;
	190	stream->avail_in = req->avail_in;
	191	stream->next_out = req->next_out;
	192	stream->avail_out = req->avail_out;
	193
	194	ret = zlib_deflate(stream, Z_FINISH);
	195	if (ret != Z_STREAM_END) {
	196	pr_debug("zlib_deflate failed %d\n", ret);
	197	return -EINVAL;
	198	}
	199
3ce858cb	200	ret = req->avail_out - stream->avail_out;
bf68e65e GU	201	pr_debug("avail_in %u, avail_out %u (consumed %u, produced %u)\n",
bf68e65e GU	202	stream->avail_in, stream->avail_out,
3ce858cb	203	req->avail_in - stream->avail_in, ret);
bf68e65e GU	204	req->next_in = stream->next_in;
	205	req->avail_in = stream->avail_in;
	206	req->next_out = stream->next_out;
	207	req->avail_out = stream->avail_out;
3ce858cb	208	return ret;
bf68e65e GU	209	}
	210
	211
	212	static int zlib_decompress_setup(struct crypto_pcomp tfm, void params,
	213	unsigned int len)
	214	{
	215	struct zlib_ctx *ctx = crypto_tfm_ctx(crypto_pcomp_tfm(tfm));
	216	struct z_stream_s *stream = &ctx->decomp_stream;
	217	struct nlattr *tb[ZLIB_DECOMP_MAX + 1];
	218	int ret = 0;
	219
	220	ret = nla_parse(tb, ZLIB_DECOMP_MAX, params, len, NULL);
	221	if (ret)
	222	return ret;
	223
	224	zlib_decomp_exit(ctx);
	225
	226	ctx->decomp_windowBits = tb[ZLIB_DECOMP_WINDOWBITS]
	227	? nla_get_u32(tb[ZLIB_DECOMP_WINDOWBITS])
	228	: DEF_WBITS;
	229
7ab24bfd	230	stream->workspace = vzalloc(zlib_inflate_workspacesize());
bf68e65e GU	231	if (!stream->workspace)
	232	return -ENOMEM;
	233
	234	ret = zlib_inflateInit2(stream, ctx->decomp_windowBits);
	235	if (ret != Z_OK) {
7ab24bfd	236	vfree(stream->workspace);
bf68e65e GU	237	stream->workspace = NULL;
	238	return -EINVAL;
	239	}
	240
	241	return 0;
	242	}
	243
	244	static int zlib_decompress_init(struct crypto_pcomp *tfm)
	245	{
	246	int ret;
	247	struct zlib_ctx *dctx = crypto_tfm_ctx(crypto_pcomp_tfm(tfm));
	248	struct z_stream_s *stream = &dctx->decomp_stream;
	249
	250	ret = zlib_inflateReset(stream);
	251	if (ret != Z_OK)
	252	return -EINVAL;
	253
	254	return 0;
	255	}
	256
	257	static int zlib_decompress_update(struct crypto_pcomp *tfm,
	258	struct comp_request *req)
	259	{
	260	int ret;
	261	struct zlib_ctx *dctx = crypto_tfm_ctx(crypto_pcomp_tfm(tfm));
	262	struct z_stream_s *stream = &dctx->decomp_stream;
	263
	264	pr_debug("avail_in %u, avail_out %u\n", req->avail_in, req->avail_out);
	265	stream->next_in = req->next_in;
	266	stream->avail_in = req->avail_in;
	267	stream->next_out = req->next_out;
	268	stream->avail_out = req->avail_out;
	269
	270	ret = zlib_inflate(stream, Z_SYNC_FLUSH);
	271	switch (ret) {
	272	case Z_OK:
	273	case Z_STREAM_END:
	274	break;
	275
	276	case Z_BUF_ERROR:
	277	pr_debug("zlib_inflate could not make progress\n");
	278	return -EAGAIN;
	279
	280	default:
	281	pr_debug("zlib_inflate failed %d\n", ret);
	282	return -EINVAL;
	283	}
	284
3ce858cb	285	ret = req->avail_out - stream->avail_out;
bf68e65e GU	286	pr_debug("avail_in %u, avail_out %u (consumed %u, produced %u)\n",
bf68e65e GU	287	stream->avail_in, stream->avail_out,
3ce858cb	288	req->avail_in - stream->avail_in, ret);
bf68e65e GU	289	req->next_in = stream->next_in;
	290	req->avail_in = stream->avail_in;
	291	req->next_out = stream->next_out;
	292	req->avail_out = stream->avail_out;
3ce858cb	293	return ret;
bf68e65e GU	294	}
	295
	296	static int zlib_decompress_final(struct crypto_pcomp *tfm,
	297	struct comp_request *req)
	298	{
	299	int ret;
	300	struct zlib_ctx *dctx = crypto_tfm_ctx(crypto_pcomp_tfm(tfm));
	301	struct z_stream_s *stream = &dctx->decomp_stream;
	302
	303	pr_debug("avail_in %u, avail_out %u\n", req->avail_in, req->avail_out);
	304	stream->next_in = req->next_in;
	305	stream->avail_in = req->avail_in;
	306	stream->next_out = req->next_out;
	307	stream->avail_out = req->avail_out;
	308
	309	if (dctx->decomp_windowBits < 0) {
	310	ret = zlib_inflate(stream, Z_SYNC_FLUSH);
	311	/*
	312	* Work around a bug in zlib, which sometimes wants to taste an
	313	* extra byte when being used in the (undocumented) raw deflate
	314	* mode. (From USAGI).
	315	*/
	316	if (ret == Z_OK && !stream->avail_in && stream->avail_out) {
	317	const void *saved_next_in = stream->next_in;
	318	u8 zerostuff = 0;
	319
	320	stream->next_in = &zerostuff;
	321	stream->avail_in = 1;
	322	ret = zlib_inflate(stream, Z_FINISH);
	323	stream->next_in = saved_next_in;
	324	stream->avail_in = 0;
	325	}
	326	} else
	327	ret = zlib_inflate(stream, Z_FINISH);
	328	if (ret != Z_STREAM_END) {
	329	pr_debug("zlib_inflate failed %d\n", ret);
	330	return -EINVAL;
	331	}
	332
3ce858cb	333	ret = req->avail_out - stream->avail_out;
bf68e65e GU	334	pr_debug("avail_in %u, avail_out %u (consumed %u, produced %u)\n",
bf68e65e GU	335	stream->avail_in, stream->avail_out,
3ce858cb	336	req->avail_in - stream->avail_in, ret);
bf68e65e GU	337	req->next_in = stream->next_in;
	338	req->avail_in = stream->avail_in;
	339	req->next_out = stream->next_out;
	340	req->avail_out = stream->avail_out;
3ce858cb	341	return ret;
bf68e65e GU	342	}
	343
	344
	345	static struct pcomp_alg zlib_alg = {
	346	.compress_setup = zlib_compress_setup,
	347	.compress_init = zlib_compress_init,
	348	.compress_update = zlib_compress_update,
	349	.compress_final = zlib_compress_final,
	350	.decompress_setup = zlib_decompress_setup,
	351	.decompress_init = zlib_decompress_init,
	352	.decompress_update = zlib_decompress_update,
	353	.decompress_final = zlib_decompress_final,
	354
	355	.base = {
	356	.cra_name = "zlib",
	357	.cra_flags = CRYPTO_ALG_TYPE_PCOMPRESS,
	358	.cra_ctxsize = sizeof(struct zlib_ctx),
	359	.cra_module = THIS_MODULE,
	360	.cra_init = zlib_init,
	361	.cra_exit = zlib_exit,
	362	}
	363	};
	364
	365	static int __init zlib_mod_init(void)
	366	{
	367	return crypto_register_pcomp(&zlib_alg);
	368	}
	369
	370	static void __exit zlib_mod_fini(void)
	371	{
	372	crypto_unregister_pcomp(&zlib_alg);
	373	}
	374
	375	module_init(zlib_mod_init);
	376	module_exit(zlib_mod_fini);
	377
	378	MODULE_LICENSE("GPL");
	379	MODULE_DESCRIPTION("Zlib Compression Algorithm");
	380	MODULE_AUTHOR("Sony Corporation");
e635e0d5	381	MODULE_ALIAS_CRYPTO("zlib");