[linux.git] / lib / decompress_unlzo.c

/*
 * LZO decompressor for the Linux kernel. Code borrowed from the lzo
 * implementation by Markus Franz Xaver Johannes Oberhumer.
 *
 * Linux kernel adaptation:
 * Copyright (C) 2009
 * Albin Tonnerre, Free Electrons <[email protected]>
 *
 * Original code:
 * Copyright (C) 1996-2005 Markus Franz Xaver Johannes Oberhumer
 * All Rights Reserved.
 *
 * lzop and the LZO library are free software; you can redistribute them
 * and/or modify them 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.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; see the file COPYING.
 * If not, write to the Free Software Foundation, Inc.,
 * 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
 *
 * Markus F.X.J. Oberhumer
 * <[email protected]>
 * http://www.oberhumer.com/opensource/lzop/
 */

#ifdef STATIC
#include "lzo/lzo1x_decompress_safe.c"
#else
#include <linux/decompress/unlzo.h>
#endif

#include <linux/types.h>
#include <linux/lzo.h>
#include <linux/decompress/mm.h>

#include <linux/compiler.h>
#include <asm/unaligned.h>

static const unsigned char lzop_magic[] = {
	0x89, 0x4c, 0x5a, 0x4f, 0x00, 0x0d, 0x0a, 0x1a, 0x0a };

#define LZO_BLOCK_SIZE        (256*1024l)
#define HEADER_HAS_FILTER      0x00000800L
#define HEADER_SIZE_MIN       (9 + 7     + 4 + 8     + 1       + 4)
#define HEADER_SIZE_MAX       (9 + 7 + 1 + 8 + 8 + 4 + 1 + 255 + 4)

STATIC inline int INIT parse_header(u8 *input, int *skip, int in_len)
{
	int l;
	u8 *parse = input;
	u8 *end = input + in_len;
	u8 level = 0;
	u16 version;

	/*
	 * Check that there's enough input to possibly have a valid header.
	 * Then it is possible to parse several fields until the minimum
	 * size may have been used.
	 */
	if (in_len < HEADER_SIZE_MIN)
		return 0;

	/* read magic: 9 first bits */
	for (l = 0; l < 9; l++) {
		if (*parse++ != lzop_magic[l])
			return 0;
	}
	/* get version (2bytes), skip library version (2),
	 * 'need to be extracted' version (2) and
	 * method (1) */
	version = get_unaligned_be16(parse);
	parse += 7;
	if (version >= 0x0940)
		level = *parse++;
	if (get_unaligned_be32(parse) & HEADER_HAS_FILTER)
		parse += 8; /* flags + filter info */
	else
		parse += 4; /* flags */

	/*
	 * At least mode, mtime_low, filename length, and checksum must
	 * be left to be parsed. If also mtime_high is present, it's OK
	 * because the next input buffer check is after reading the
	 * filename length.
	 */
	if (end - parse < 8 + 1 + 4)
		return 0;

	/* skip mode and mtime_low */
	parse += 8;
	if (version >= 0x0940)
		parse += 4;	/* skip mtime_high */

	l = *parse++;
	/* don't care about the file name, and skip checksum */
	if (end - parse < l + 4)
		return 0;
	parse += l + 4;

	*skip = parse - input;
	return 1;
}

STATIC inline int INIT unlzo(u8 *input, int in_len,
				int (*fill) (void *, unsigned int),
				int (*flush) (void *, unsigned int),
				u8 *output, int *posp,
				void (*error) (char *x))
{
	u8 r = 0;
	int skip = 0;
	u32 src_len, dst_len;
	size_t tmp;
	u8 *in_buf, *in_buf_save, *out_buf;
	int ret = -1;

	if (output) {
		out_buf = output;
	} else if (!flush) {
		error("NULL output pointer and no flush function provided");
		goto exit;
	} else {
		out_buf = malloc(LZO_BLOCK_SIZE);
		if (!out_buf) {
			error("Could not allocate output buffer");
			goto exit;
		}
	}

	if (input && fill) {
		error("Both input pointer and fill function provided, don't know what to do");
		goto exit_1;
	} else if (input) {
		in_buf = input;
	} else if (!fill) {
		error("NULL input pointer and missing fill function");
		goto exit_1;
	} else {
		in_buf = malloc(lzo1x_worst_compress(LZO_BLOCK_SIZE));
		if (!in_buf) {
			error("Could not allocate input buffer");
			goto exit_1;
		}
	}
	in_buf_save = in_buf;

	if (posp)
		*posp = 0;

	if (fill) {
		/*
		 * Start from in_buf + HEADER_SIZE_MAX to make it possible
		 * to use memcpy() to copy the unused data to the beginning
		 * of the buffer. This way memmove() isn't needed which
		 * is missing from pre-boot environments of most archs.
		 */
		in_buf += HEADER_SIZE_MAX;
		in_len = fill(in_buf, HEADER_SIZE_MAX);
	}

	if (!parse_header(in_buf, &skip, in_len)) {
		error("invalid header");
		goto exit_2;
	}
	in_buf += skip;
	in_len -= skip;

	if (fill) {
		/* Move the unused data to the beginning of the buffer. */
		memcpy(in_buf_save, in_buf, in_len);
		in_buf = in_buf_save;
	}

	if (posp)
		*posp = skip;

	for (;;) {
		/* read uncompressed block size */
		if (fill && in_len < 4) {
			skip = fill(in_buf + in_len, 4 - in_len);
			if (skip > 0)
				in_len += skip;
		}
		if (in_len < 4) {
			error("file corrupted");
			goto exit_2;
		}
		dst_len = get_unaligned_be32(in_buf);
		in_buf += 4;
		in_len -= 4;

		/* exit if last block */
		if (dst_len == 0) {
			if (posp)
				*posp += 4;
			break;
		}

		if (dst_len > LZO_BLOCK_SIZE) {
			error("dest len longer than block size");
			goto exit_2;
		}

		/* read compressed block size, and skip block checksum info */
		if (fill && in_len < 8) {
			skip = fill(in_buf + in_len, 8 - in_len);
			if (skip > 0)
				in_len += skip;
		}
		if (in_len < 8) {
			error("file corrupted");
			goto exit_2;
		}
		src_len = get_unaligned_be32(in_buf);
		in_buf += 8;
		in_len -= 8;

		if (src_len <= 0 || src_len > dst_len) {
			error("file corrupted");
			goto exit_2;
		}

		/* decompress */
		if (fill && in_len < src_len) {
			skip = fill(in_buf + in_len, src_len - in_len);
			if (skip > 0)
				in_len += skip;
		}
		if (in_len < src_len) {
			error("file corrupted");
			goto exit_2;
		}
		tmp = dst_len;

		/* When the input data is not compressed at all,
		 * lzo1x_decompress_safe will fail, so call memcpy()
		 * instead */
		if (unlikely(dst_len == src_len))
			memcpy(out_buf, in_buf, src_len);
		else {
			r = lzo1x_decompress_safe((u8 *) in_buf, src_len,
						out_buf, &tmp);

			if (r != LZO_E_OK || dst_len != tmp) {
				error("Compressed data violation");
				goto exit_2;
			}
		}

		if (flush && flush(out_buf, dst_len) != dst_len)
			goto exit_2;
		if (output)
			out_buf += dst_len;
		if (posp)
			*posp += src_len + 12;

		in_buf += src_len;
		in_len -= src_len;
		if (fill) {
			/*
			 * If there happens to still be unused data left in
			 * in_buf, move it to the beginning of the buffer.
			 * Use a loop to avoid memmove() dependency.
			 */
			if (in_len > 0)
				for (skip = 0; skip < in_len; ++skip)
					in_buf_save[skip] = in_buf[skip];
			in_buf = in_buf_save;
		}
	}

	ret = 0;
exit_2:
	if (!input)
		free(in_buf_save);
exit_1:
	if (!output)
		free(out_buf);
exit:
	return ret;
}

#define decompress unlzo
Commit	Line	Data
7dd65feb AT	1	/*
	2	* LZO decompressor for the Linux kernel. Code borrowed from the lzo
	3	* implementation by Markus Franz Xaver Johannes Oberhumer.
	4	*
	5	* Linux kernel adaptation:
	6	* Copyright (C) 2009
	7	* Albin Tonnerre, Free Electrons <[email protected]>
	8	*
	9	* Original code:
	10	* Copyright (C) 1996-2005 Markus Franz Xaver Johannes Oberhumer
	11	* All Rights Reserved.
	12	*
	13	* lzop and the LZO library are free software; you can redistribute them
	14	* and/or modify them under the terms of the GNU General Public License as
	15	* published by the Free Software Foundation; either version 2 of
	16	* the License, or (at your option) any later version.
	17	*
	18	* This program is distributed in the hope that it will be useful,
	19	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	20	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	21	* GNU General Public License for more details.
	22	*
	23	* You should have received a copy of the GNU General Public License
	24	* along with this program; see the file COPYING.
	25	* If not, write to the Free Software Foundation, Inc.,
	26	* 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
	27	*
	28	* Markus F.X.J. Oberhumer
	29	* <[email protected]>
	30	* http://www.oberhumer.com/opensource/lzop/
	31	*/
	32
	33	#ifdef STATIC
b6bec26c	34	#include "lzo/lzo1x_decompress_safe.c"
7dd65feb	35	#else
7dd65feb AT	36	#include <linux/decompress/unlzo.h>
	37	#endif
	38
	39	#include <linux/types.h>
	40	#include <linux/lzo.h>
	41	#include <linux/decompress/mm.h>
	42
	43	#include <linux/compiler.h>
	44	#include <asm/unaligned.h>
	45
	46	static const unsigned char lzop_magic[] = {
	47	0x89, 0x4c, 0x5a, 0x4f, 0x00, 0x0d, 0x0a, 0x1a, 0x0a };
	48
	49	#define LZO_BLOCK_SIZE (256*1024l)
	50	#define HEADER_HAS_FILTER 0x00000800L
5a3f81a7 LC	51	#define HEADER_SIZE_MIN (9 + 7 + 4 + 8 + 1 + 4)
5a3f81a7 LC	52	#define HEADER_SIZE_MAX (9 + 7 + 1 + 8 + 8 + 4 + 1 + 255 + 4)
7dd65feb	53
5a3f81a7	54	STATIC inline int INIT parse_header(u8 input, int skip, int in_len)
7dd65feb AT	55	{
	56	int l;
	57	u8 *parse = input;
5a3f81a7	58	u8 *end = input + in_len;
7dd65feb AT	59	u8 level = 0;
	60	u16 version;
	61
5a3f81a7 LC	62	/*
	63	* Check that there's enough input to possibly have a valid header.
	64	* Then it is possible to parse several fields until the minimum
	65	* size may have been used.
	66	*/
	67	if (in_len < HEADER_SIZE_MIN)
	68	return 0;
	69
7dd65feb AT	70	/* read magic: 9 first bits */
	71	for (l = 0; l < 9; l++) {
	72	if (*parse++ != lzop_magic[l])
	73	return 0;
	74	}
	75	/* get version (2bytes), skip library version (2),
	76	* 'need to be extracted' version (2) and
	77	* method (1) */
	78	version = get_unaligned_be16(parse);
	79	parse += 7;
	80	if (version >= 0x0940)
	81	level = *parse++;
	82	if (get_unaligned_be32(parse) & HEADER_HAS_FILTER)
	83	parse += 8; /* flags + filter info */
	84	else
	85	parse += 4; /* flags */
	86
5a3f81a7 LC	87	/*
	88	* At least mode, mtime_low, filename length, and checksum must
	89	* be left to be parsed. If also mtime_high is present, it's OK
	90	* because the next input buffer check is after reading the
	91	* filename length.
	92	*/
	93	if (end - parse < 8 + 1 + 4)
	94	return 0;
	95
7dd65feb AT	96	/* skip mode and mtime_low */
	97	parse += 8;
	98	if (version >= 0x0940)
	99	parse += 4; /* skip mtime_high */
	100
	101	l = *parse++;
	102	/* don't care about the file name, and skip checksum */
5a3f81a7 LC	103	if (end - parse < l + 4)
5a3f81a7 LC	104	return 0;
7dd65feb AT	105	parse += l + 4;
	106
	107	*skip = parse - input;
	108	return 1;
	109	}
	110
	111	STATIC inline int INIT unlzo(u8 *input, int in_len,
	112	int (fill) (void , unsigned int),
	113	int (flush) (void , unsigned int),
	114	u8 output, int posp,
93685ad2	115	void (error) (char x))
7dd65feb	116	{
5a3f81a7 LC	117	u8 r = 0;
5a3f81a7 LC	118	int skip = 0;
7dd65feb AT	119	u32 src_len, dst_len;
	120	size_t tmp;
	121	u8 in_buf, in_buf_save, *out_buf;
ccdb4004	122	int ret = -1;
7dd65feb	123
7dd65feb AT	124	if (output) {
	125	out_buf = output;
	126	} else if (!flush) {
	127	error("NULL output pointer and no flush function provided");
	128	goto exit;
	129	} else {
	130	out_buf = malloc(LZO_BLOCK_SIZE);
	131	if (!out_buf) {
	132	error("Could not allocate output buffer");
	133	goto exit;
	134	}
	135	}
	136
	137	if (input && fill) {
	138	error("Both input pointer and fill function provided, don't know what to do");
	139	goto exit_1;
	140	} else if (input) {
	141	in_buf = input;
fb7fa589 LC	142	} else if (!fill) {
fb7fa589 LC	143	error("NULL input pointer and missing fill function");
7dd65feb AT	144	goto exit_1;
	145	} else {
	146	in_buf = malloc(lzo1x_worst_compress(LZO_BLOCK_SIZE));
	147	if (!in_buf) {
	148	error("Could not allocate input buffer");
	149	goto exit_1;
	150	}
	151	}
	152	in_buf_save = in_buf;
	153
	154	if (posp)
	155	*posp = 0;
	156
fb7fa589 LC	157	if (fill) {
	158	/*
	159	* Start from in_buf + HEADER_SIZE_MAX to make it possible
	160	* to use memcpy() to copy the unused data to the beginning
	161	* of the buffer. This way memmove() isn't needed which
	162	* is missing from pre-boot environments of most archs.
	163	*/
	164	in_buf += HEADER_SIZE_MAX;
	165	in_len = fill(in_buf, HEADER_SIZE_MAX);
	166	}
7dd65feb	167
fb7fa589	168	if (!parse_header(in_buf, &skip, in_len)) {
7dd65feb AT	169	error("invalid header");
	170	goto exit_2;
	171	}
	172	in_buf += skip;
5a3f81a7	173	in_len -= skip;
7dd65feb	174
fb7fa589 LC	175	if (fill) {
	176	/* Move the unused data to the beginning of the buffer. */
	177	memcpy(in_buf_save, in_buf, in_len);
	178	in_buf = in_buf_save;
	179	}
	180
7dd65feb AT	181	if (posp)
	182	*posp = skip;
	183
	184	for (;;) {
	185	/* read uncompressed block size */
fb7fa589 LC	186	if (fill && in_len < 4) {
	187	skip = fill(in_buf + in_len, 4 - in_len);
	188	if (skip > 0)
	189	in_len += skip;
	190	}
5a3f81a7 LC	191	if (in_len < 4) {
	192	error("file corrupted");
	193	goto exit_2;
	194	}
7dd65feb AT	195	dst_len = get_unaligned_be32(in_buf);
7dd65feb AT	196	in_buf += 4;
5a3f81a7	197	in_len -= 4;
7dd65feb AT	198
	199	/* exit if last block */
	200	if (dst_len == 0) {
	201	if (posp)
	202	*posp += 4;
	203	break;
	204	}
	205
	206	if (dst_len > LZO_BLOCK_SIZE) {
	207	error("dest len longer than block size");
	208	goto exit_2;
	209	}
	210
	211	/* read compressed block size, and skip block checksum info */
fb7fa589 LC	212	if (fill && in_len < 8) {
	213	skip = fill(in_buf + in_len, 8 - in_len);
	214	if (skip > 0)
	215	in_len += skip;
	216	}
5a3f81a7 LC	217	if (in_len < 8) {
	218	error("file corrupted");
	219	goto exit_2;
	220	}
7dd65feb AT	221	src_len = get_unaligned_be32(in_buf);
7dd65feb AT	222	in_buf += 8;
5a3f81a7	223	in_len -= 8;
7dd65feb	224
fb7fa589	225	if (src_len <= 0 \|\| src_len > dst_len) {
7dd65feb AT	226	error("file corrupted");
	227	goto exit_2;
	228	}
	229
	230	/* decompress */
fb7fa589 LC	231	if (fill && in_len < src_len) {
	232	skip = fill(in_buf + in_len, src_len - in_len);
	233	if (skip > 0)
	234	in_len += skip;
	235	}
	236	if (in_len < src_len) {
	237	error("file corrupted");
	238	goto exit_2;
	239	}
7dd65feb	240	tmp = dst_len;
ccdb4004 AT	241
	242	/* When the input data is not compressed at all,
	243	* lzo1x_decompress_safe will fail, so call memcpy()
	244	* instead */
	245	if (unlikely(dst_len == src_len))
	246	memcpy(out_buf, in_buf, src_len);
	247	else {
	248	r = lzo1x_decompress_safe((u8 *) in_buf, src_len,
7dd65feb AT	249	out_buf, &tmp);
7dd65feb AT	250
ccdb4004 AT	251	if (r != LZO_E_OK \|\| dst_len != tmp) {
	252	error("Compressed data violation");
	253	goto exit_2;
	254	}
7dd65feb AT	255	}
7dd65feb AT	256
8f9b54a3 LC	257	if (flush && flush(out_buf, dst_len) != dst_len)
8f9b54a3 LC	258	goto exit_2;
7dd65feb AT	259	if (output)
	260	out_buf += dst_len;
	261	if (posp)
	262	*posp += src_len + 12;
fb7fa589 LC	263
	264	in_buf += src_len;
	265	in_len -= src_len;
7dd65feb	266	if (fill) {
fb7fa589 LC	267	/*
	268	* If there happens to still be unused data left in
	269	* in_buf, move it to the beginning of the buffer.
	270	* Use a loop to avoid memmove() dependency.
	271	*/
	272	if (in_len > 0)
	273	for (skip = 0; skip < in_len; ++skip)
	274	in_buf_save[skip] = in_buf[skip];
7dd65feb	275	in_buf = in_buf_save;
5a3f81a7	276	}
7dd65feb AT	277	}
7dd65feb AT	278
ccdb4004	279	ret = 0;
7dd65feb AT	280	exit_2:
7dd65feb AT	281	if (!input)
35f15268	282	free(in_buf_save);
7dd65feb AT	283	exit_1:
	284	if (!output)
	285	free(out_buf);
	286	exit:
ccdb4004	287	return ret;
7dd65feb AT	288	}
	289
	290	#define decompress unlzo