[mirror_ubuntu-bionic-kernel.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 <albin.tonnerre@free-electrons.com>
 *
 * 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
 * <markus@oberhumer.com>
 * http://www.oberhumer.com/opensource/lzop/
 */

#ifdef STATIC
#define PREBOOT
#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 long INIT parse_header(u8 *input, long *skip, long 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 int INIT unlzo(u8 *input, long in_len,
				long (*fill)(void *, unsigned long),
				long (*flush)(void *, unsigned long),
				u8 *output, long *posp,
				void (*error) (char *x))
{
	u8 r = 0;
	long 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;
}

#ifdef PREBOOT
STATIC int INIT __decompress(unsigned char *buf, long len,
			   long (*fill)(void*, unsigned long),
			   long (*flush)(void*, unsigned long),
			   unsigned char *out_buf, long olen,
			   long *pos,
			   void (*error)(char *x))
{
	return unlzo(buf, len, fill, flush, out_buf, pos, error);
}
#endif
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 <albin.tonnerre@free-electrons.com>
	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	* <markus@oberhumer.com>
	30	* http://www.oberhumer.com/opensource/lzop/
	31	*/
	32
	33	#ifdef STATIC
2d3862d2	34	#define PREBOOT
b6bec26c	35	#include "lzo/lzo1x_decompress_safe.c"
7dd65feb	36	#else
7dd65feb AT	37	#include <linux/decompress/unlzo.h>
	38	#endif
	39
	40	#include <linux/types.h>
	41	#include <linux/lzo.h>
	42	#include <linux/decompress/mm.h>
	43
	44	#include <linux/compiler.h>
	45	#include <asm/unaligned.h>
	46
	47	static const unsigned char lzop_magic[] = {
	48	0x89, 0x4c, 0x5a, 0x4f, 0x00, 0x0d, 0x0a, 0x1a, 0x0a };
	49
	50	#define LZO_BLOCK_SIZE (256*1024l)
	51	#define HEADER_HAS_FILTER 0x00000800L
5a3f81a7 LC	52	#define HEADER_SIZE_MIN (9 + 7 + 4 + 8 + 1 + 4)
5a3f81a7 LC	53	#define HEADER_SIZE_MAX (9 + 7 + 1 + 8 + 8 + 4 + 1 + 255 + 4)
7dd65feb	54
d97b07c5	55	STATIC inline long INIT parse_header(u8 input, long skip, long in_len)
7dd65feb AT	56	{
	57	int l;
	58	u8 *parse = input;
5a3f81a7	59	u8 *end = input + in_len;
7dd65feb AT	60	u8 level = 0;
	61	u16 version;
	62
5a3f81a7 LC	63	/*
	64	* Check that there's enough input to possibly have a valid header.
	65	* Then it is possible to parse several fields until the minimum
	66	* size may have been used.
	67	*/
	68	if (in_len < HEADER_SIZE_MIN)
	69	return 0;
	70
7dd65feb AT	71	/* read magic: 9 first bits */
	72	for (l = 0; l < 9; l++) {
	73	if (*parse++ != lzop_magic[l])
	74	return 0;
	75	}
	76	/* get version (2bytes), skip library version (2),
	77	* 'need to be extracted' version (2) and
	78	* method (1) */
	79	version = get_unaligned_be16(parse);
	80	parse += 7;
	81	if (version >= 0x0940)
	82	level = *parse++;
	83	if (get_unaligned_be32(parse) & HEADER_HAS_FILTER)
	84	parse += 8; /* flags + filter info */
	85	else
	86	parse += 4; /* flags */
	87
5a3f81a7 LC	88	/*
	89	* At least mode, mtime_low, filename length, and checksum must
	90	* be left to be parsed. If also mtime_high is present, it's OK
	91	* because the next input buffer check is after reading the
	92	* filename length.
	93	*/
	94	if (end - parse < 8 + 1 + 4)
	95	return 0;
	96
7dd65feb AT	97	/* skip mode and mtime_low */
	98	parse += 8;
	99	if (version >= 0x0940)
	100	parse += 4; /* skip mtime_high */
	101
	102	l = *parse++;
	103	/* don't care about the file name, and skip checksum */
5a3f81a7 LC	104	if (end - parse < l + 4)
5a3f81a7 LC	105	return 0;
7dd65feb AT	106	parse += l + 4;
	107
	108	*skip = parse - input;
	109	return 1;
	110	}
	111
d97b07c5 YL	112	STATIC int INIT unlzo(u8 *input, long in_len,
	113	long (fill)(void , unsigned long),
	114	long (flush)(void , unsigned long),
	115	u8 output, long posp,
93685ad2	116	void (error) (char x))
7dd65feb	117	{
5a3f81a7	118	u8 r = 0;
d97b07c5	119	long skip = 0;
7dd65feb AT	120	u32 src_len, dst_len;
	121	size_t tmp;
	122	u8 in_buf, in_buf_save, *out_buf;
ccdb4004	123	int ret = -1;
7dd65feb	124
7dd65feb AT	125	if (output) {
	126	out_buf = output;
	127	} else if (!flush) {
	128	error("NULL output pointer and no flush function provided");
	129	goto exit;
	130	} else {
	131	out_buf = malloc(LZO_BLOCK_SIZE);
	132	if (!out_buf) {
	133	error("Could not allocate output buffer");
	134	goto exit;
	135	}
	136	}
	137
	138	if (input && fill) {
	139	error("Both input pointer and fill function provided, don't know what to do");
	140	goto exit_1;
	141	} else if (input) {
	142	in_buf = input;
fb7fa589 LC	143	} else if (!fill) {
fb7fa589 LC	144	error("NULL input pointer and missing fill function");
7dd65feb AT	145	goto exit_1;
	146	} else {
	147	in_buf = malloc(lzo1x_worst_compress(LZO_BLOCK_SIZE));
	148	if (!in_buf) {
	149	error("Could not allocate input buffer");
	150	goto exit_1;
	151	}
	152	}
	153	in_buf_save = in_buf;
	154
	155	if (posp)
	156	*posp = 0;
	157
fb7fa589 LC	158	if (fill) {
	159	/*
	160	* Start from in_buf + HEADER_SIZE_MAX to make it possible
	161	* to use memcpy() to copy the unused data to the beginning
	162	* of the buffer. This way memmove() isn't needed which
	163	* is missing from pre-boot environments of most archs.
	164	*/
	165	in_buf += HEADER_SIZE_MAX;
	166	in_len = fill(in_buf, HEADER_SIZE_MAX);
	167	}
7dd65feb	168
fb7fa589	169	if (!parse_header(in_buf, &skip, in_len)) {
7dd65feb AT	170	error("invalid header");
	171	goto exit_2;
	172	}
	173	in_buf += skip;
5a3f81a7	174	in_len -= skip;
7dd65feb	175
fb7fa589 LC	176	if (fill) {
	177	/* Move the unused data to the beginning of the buffer. */
	178	memcpy(in_buf_save, in_buf, in_len);
	179	in_buf = in_buf_save;
	180	}
	181
7dd65feb AT	182	if (posp)
	183	*posp = skip;
	184
	185	for (;;) {
	186	/* read uncompressed block size */
fb7fa589 LC	187	if (fill && in_len < 4) {
	188	skip = fill(in_buf + in_len, 4 - in_len);
	189	if (skip > 0)
	190	in_len += skip;
	191	}
5a3f81a7 LC	192	if (in_len < 4) {
	193	error("file corrupted");
	194	goto exit_2;
	195	}
7dd65feb AT	196	dst_len = get_unaligned_be32(in_buf);
7dd65feb AT	197	in_buf += 4;
5a3f81a7	198	in_len -= 4;
7dd65feb AT	199
	200	/* exit if last block */
	201	if (dst_len == 0) {
	202	if (posp)
	203	*posp += 4;
	204	break;
	205	}
	206
	207	if (dst_len > LZO_BLOCK_SIZE) {
	208	error("dest len longer than block size");
	209	goto exit_2;
	210	}
	211
	212	/* read compressed block size, and skip block checksum info */
fb7fa589 LC	213	if (fill && in_len < 8) {
	214	skip = fill(in_buf + in_len, 8 - in_len);
	215	if (skip > 0)
	216	in_len += skip;
	217	}
5a3f81a7 LC	218	if (in_len < 8) {
	219	error("file corrupted");
	220	goto exit_2;
	221	}
7dd65feb AT	222	src_len = get_unaligned_be32(in_buf);
7dd65feb AT	223	in_buf += 8;
5a3f81a7	224	in_len -= 8;
7dd65feb	225
fb7fa589	226	if (src_len <= 0 \|\| src_len > dst_len) {
7dd65feb AT	227	error("file corrupted");
	228	goto exit_2;
	229	}
	230
	231	/* decompress */
fb7fa589 LC	232	if (fill && in_len < src_len) {
	233	skip = fill(in_buf + in_len, src_len - in_len);
	234	if (skip > 0)
	235	in_len += skip;
	236	}
	237	if (in_len < src_len) {
	238	error("file corrupted");
	239	goto exit_2;
	240	}
7dd65feb	241	tmp = dst_len;
ccdb4004 AT	242
	243	/* When the input data is not compressed at all,
	244	* lzo1x_decompress_safe will fail, so call memcpy()
	245	* instead */
	246	if (unlikely(dst_len == src_len))
	247	memcpy(out_buf, in_buf, src_len);
	248	else {
	249	r = lzo1x_decompress_safe((u8 *) in_buf, src_len,
7dd65feb AT	250	out_buf, &tmp);
7dd65feb AT	251
ccdb4004 AT	252	if (r != LZO_E_OK \|\| dst_len != tmp) {
	253	error("Compressed data violation");
	254	goto exit_2;
	255	}
7dd65feb AT	256	}
7dd65feb AT	257
8f9b54a3 LC	258	if (flush && flush(out_buf, dst_len) != dst_len)
8f9b54a3 LC	259	goto exit_2;
7dd65feb AT	260	if (output)
	261	out_buf += dst_len;
	262	if (posp)
	263	*posp += src_len + 12;
fb7fa589 LC	264
	265	in_buf += src_len;
	266	in_len -= src_len;
7dd65feb	267	if (fill) {
fb7fa589 LC	268	/*
	269	* If there happens to still be unused data left in
	270	* in_buf, move it to the beginning of the buffer.
	271	* Use a loop to avoid memmove() dependency.
	272	*/
	273	if (in_len > 0)
	274	for (skip = 0; skip < in_len; ++skip)
	275	in_buf_save[skip] = in_buf[skip];
7dd65feb	276	in_buf = in_buf_save;
5a3f81a7	277	}
7dd65feb AT	278	}
7dd65feb AT	279
ccdb4004	280	ret = 0;
7dd65feb AT	281	exit_2:
7dd65feb AT	282	if (!input)
35f15268	283	free(in_buf_save);
7dd65feb AT	284	exit_1:
	285	if (!output)
	286	free(out_buf);
	287	exit:
ccdb4004	288	return ret;
7dd65feb AT	289	}
7dd65feb AT	290
2d3862d2 YL	291	#ifdef PREBOOT
	292	STATIC int INIT __decompress(unsigned char *buf, long len,
	293	long (fill)(void, unsigned long),
	294	long (flush)(void, unsigned long),
	295	unsigned char *out_buf, long olen,
	296	long *pos,
	297	void (error)(char x))
	298	{
	299	return unlzo(buf, len, fill, flush, out_buf, pos, error);
	300	}
	301	#endif