[linux.git] / lib / decompress_unlzo.c

// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * 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.
 *
 * Markus F.X.J. Oberhumer
 * <[email protected]>
 * 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;
	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)
		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
45a46873	1	// SPDX-License-Identifier: GPL-2.0-or-later
7dd65feb AT	2	/*
	3	* LZO decompressor for the Linux kernel. Code borrowed from the lzo
	4	* implementation by Markus Franz Xaver Johannes Oberhumer.
	5	*
	6	* Linux kernel adaptation:
	7	* Copyright (C) 2009
	8	* Albin Tonnerre, Free Electrons <[email protected]>
	9	*
	10	* Original code:
	11	* Copyright (C) 1996-2005 Markus Franz Xaver Johannes Oberhumer
	12	* All Rights Reserved.
	13	*
7dd65feb AT	14	* Markus F.X.J. Oberhumer
	15	* <[email protected]>
	16	* http://www.oberhumer.com/opensource/lzop/
	17	*/
	18
	19	#ifdef STATIC
2d3862d2	20	#define PREBOOT
b6bec26c	21	#include "lzo/lzo1x_decompress_safe.c"
7dd65feb	22	#else
7dd65feb AT	23	#include <linux/decompress/unlzo.h>
	24	#endif
	25
	26	#include <linux/types.h>
	27	#include <linux/lzo.h>
	28	#include <linux/decompress/mm.h>
	29
	30	#include <linux/compiler.h>
	31	#include <asm/unaligned.h>
	32
	33	static const unsigned char lzop_magic[] = {
	34	0x89, 0x4c, 0x5a, 0x4f, 0x00, 0x0d, 0x0a, 0x1a, 0x0a };
	35
	36	#define LZO_BLOCK_SIZE (256*1024l)
	37	#define HEADER_HAS_FILTER 0x00000800L
5a3f81a7 LC	38	#define HEADER_SIZE_MIN (9 + 7 + 4 + 8 + 1 + 4)
5a3f81a7 LC	39	#define HEADER_SIZE_MAX (9 + 7 + 1 + 8 + 8 + 4 + 1 + 255 + 4)
7dd65feb	40
d97b07c5	41	STATIC inline long INIT parse_header(u8 input, long skip, long in_len)
7dd65feb AT	42	{
	43	int l;
	44	u8 *parse = input;
5a3f81a7	45	u8 *end = input + in_len;
7dd65feb AT	46	u16 version;
7dd65feb AT	47
5a3f81a7 LC	48	/*
	49	* Check that there's enough input to possibly have a valid header.
	50	* Then it is possible to parse several fields until the minimum
	51	* size may have been used.
	52	*/
	53	if (in_len < HEADER_SIZE_MIN)
	54	return 0;
	55
7dd65feb AT	56	/* read magic: 9 first bits */
	57	for (l = 0; l < 9; l++) {
	58	if (*parse++ != lzop_magic[l])
	59	return 0;
	60	}
	61	/* get version (2bytes), skip library version (2),
	62	* 'need to be extracted' version (2) and
	63	* method (1) */
	64	version = get_unaligned_be16(parse);
	65	parse += 7;
	66	if (version >= 0x0940)
3b523483	67	parse++;
7dd65feb AT	68	if (get_unaligned_be32(parse) & HEADER_HAS_FILTER)
	69	parse += 8; /* flags + filter info */
	70	else
	71	parse += 4; /* flags */
	72
5a3f81a7 LC	73	/*
	74	* At least mode, mtime_low, filename length, and checksum must
	75	* be left to be parsed. If also mtime_high is present, it's OK
	76	* because the next input buffer check is after reading the
	77	* filename length.
	78	*/
	79	if (end - parse < 8 + 1 + 4)
	80	return 0;
	81
7dd65feb AT	82	/* skip mode and mtime_low */
	83	parse += 8;
	84	if (version >= 0x0940)
	85	parse += 4; /* skip mtime_high */
	86
	87	l = *parse++;
	88	/* don't care about the file name, and skip checksum */
5a3f81a7 LC	89	if (end - parse < l + 4)
5a3f81a7 LC	90	return 0;
7dd65feb AT	91	parse += l + 4;
	92
	93	*skip = parse - input;
	94	return 1;
	95	}
	96
d97b07c5 YL	97	STATIC int INIT unlzo(u8 *input, long in_len,
	98	long (fill)(void , unsigned long),
	99	long (flush)(void , unsigned long),
	100	u8 output, long posp,
93685ad2	101	void (error) (char x))
7dd65feb	102	{
5a3f81a7	103	u8 r = 0;
d97b07c5	104	long skip = 0;
7dd65feb AT	105	u32 src_len, dst_len;
	106	size_t tmp;
	107	u8 in_buf, in_buf_save, *out_buf;
ccdb4004	108	int ret = -1;
7dd65feb	109
7dd65feb AT	110	if (output) {
	111	out_buf = output;
	112	} else if (!flush) {
	113	error("NULL output pointer and no flush function provided");
	114	goto exit;
	115	} else {
	116	out_buf = malloc(LZO_BLOCK_SIZE);
	117	if (!out_buf) {
	118	error("Could not allocate output buffer");
	119	goto exit;
	120	}
	121	}
	122
	123	if (input && fill) {
	124	error("Both input pointer and fill function provided, don't know what to do");
	125	goto exit_1;
	126	} else if (input) {
	127	in_buf = input;
fb7fa589 LC	128	} else if (!fill) {
fb7fa589 LC	129	error("NULL input pointer and missing fill function");
7dd65feb AT	130	goto exit_1;
	131	} else {
	132	in_buf = malloc(lzo1x_worst_compress(LZO_BLOCK_SIZE));
	133	if (!in_buf) {
	134	error("Could not allocate input buffer");
	135	goto exit_1;
	136	}
	137	}
	138	in_buf_save = in_buf;
	139
	140	if (posp)
	141	*posp = 0;
	142
fb7fa589 LC	143	if (fill) {
	144	/*
	145	* Start from in_buf + HEADER_SIZE_MAX to make it possible
	146	* to use memcpy() to copy the unused data to the beginning
	147	* of the buffer. This way memmove() isn't needed which
	148	* is missing from pre-boot environments of most archs.
	149	*/
	150	in_buf += HEADER_SIZE_MAX;
	151	in_len = fill(in_buf, HEADER_SIZE_MAX);
	152	}
7dd65feb	153
fb7fa589	154	if (!parse_header(in_buf, &skip, in_len)) {
7dd65feb AT	155	error("invalid header");
	156	goto exit_2;
	157	}
	158	in_buf += skip;
5a3f81a7	159	in_len -= skip;
7dd65feb	160
fb7fa589 LC	161	if (fill) {
	162	/* Move the unused data to the beginning of the buffer. */
	163	memcpy(in_buf_save, in_buf, in_len);
	164	in_buf = in_buf_save;
	165	}
	166
7dd65feb AT	167	if (posp)
	168	*posp = skip;
	169
	170	for (;;) {
	171	/* read uncompressed block size */
fb7fa589 LC	172	if (fill && in_len < 4) {
	173	skip = fill(in_buf + in_len, 4 - in_len);
	174	if (skip > 0)
	175	in_len += skip;
	176	}
5a3f81a7 LC	177	if (in_len < 4) {
	178	error("file corrupted");
	179	goto exit_2;
	180	}
7dd65feb AT	181	dst_len = get_unaligned_be32(in_buf);
7dd65feb AT	182	in_buf += 4;
5a3f81a7	183	in_len -= 4;
7dd65feb AT	184
	185	/* exit if last block */
	186	if (dst_len == 0) {
	187	if (posp)
	188	*posp += 4;
	189	break;
	190	}
	191
	192	if (dst_len > LZO_BLOCK_SIZE) {
	193	error("dest len longer than block size");
	194	goto exit_2;
	195	}
	196
	197	/* read compressed block size, and skip block checksum info */
fb7fa589 LC	198	if (fill && in_len < 8) {
	199	skip = fill(in_buf + in_len, 8 - in_len);
	200	if (skip > 0)
	201	in_len += skip;
	202	}
5a3f81a7 LC	203	if (in_len < 8) {
	204	error("file corrupted");
	205	goto exit_2;
	206	}
7dd65feb AT	207	src_len = get_unaligned_be32(in_buf);
7dd65feb AT	208	in_buf += 8;
5a3f81a7	209	in_len -= 8;
7dd65feb	210
fb7fa589	211	if (src_len <= 0 \|\| src_len > dst_len) {
7dd65feb AT	212	error("file corrupted");
	213	goto exit_2;
	214	}
	215
	216	/* decompress */
fb7fa589 LC	217	if (fill && in_len < src_len) {
	218	skip = fill(in_buf + in_len, src_len - in_len);
	219	if (skip > 0)
	220	in_len += skip;
	221	}
	222	if (in_len < src_len) {
	223	error("file corrupted");
	224	goto exit_2;
	225	}
7dd65feb	226	tmp = dst_len;
ccdb4004 AT	227
	228	/* When the input data is not compressed at all,
	229	* lzo1x_decompress_safe will fail, so call memcpy()
	230	* instead */
	231	if (unlikely(dst_len == src_len))
	232	memcpy(out_buf, in_buf, src_len);
	233	else {
	234	r = lzo1x_decompress_safe((u8 *) in_buf, src_len,
7dd65feb AT	235	out_buf, &tmp);
7dd65feb AT	236
ccdb4004 AT	237	if (r != LZO_E_OK \|\| dst_len != tmp) {
	238	error("Compressed data violation");
	239	goto exit_2;
	240	}
7dd65feb AT	241	}
7dd65feb AT	242
8f9b54a3 LC	243	if (flush && flush(out_buf, dst_len) != dst_len)
8f9b54a3 LC	244	goto exit_2;
7dd65feb AT	245	if (output)
	246	out_buf += dst_len;
	247	if (posp)
	248	*posp += src_len + 12;
fb7fa589 LC	249
	250	in_buf += src_len;
	251	in_len -= src_len;
7dd65feb	252	if (fill) {
fb7fa589 LC	253	/*
	254	* If there happens to still be unused data left in
	255	* in_buf, move it to the beginning of the buffer.
	256	* Use a loop to avoid memmove() dependency.
	257	*/
	258	if (in_len > 0)
	259	for (skip = 0; skip < in_len; ++skip)
	260	in_buf_save[skip] = in_buf[skip];
7dd65feb	261	in_buf = in_buf_save;
5a3f81a7	262	}
7dd65feb AT	263	}
7dd65feb AT	264
ccdb4004	265	ret = 0;
7dd65feb AT	266	exit_2:
7dd65feb AT	267	if (!input)
35f15268	268	free(in_buf_save);
7dd65feb AT	269	exit_1:
	270	if (!output)
	271	free(out_buf);
	272	exit:
ccdb4004	273	return ret;
7dd65feb AT	274	}
7dd65feb AT	275
2d3862d2 YL	276	#ifdef PREBOOT
	277	STATIC int INIT __decompress(unsigned char *buf, long len,
	278	long (fill)(void, unsigned long),
	279	long (flush)(void, unsigned long),
	280	unsigned char *out_buf, long olen,
	281	long *pos,
	282	void (error)(char x))
	283	{
	284	return unlzo(buf, len, fill, flush, out_buf, pos, error);
	285	}
	286	#endif