291 lines
6.8 KiB
C
Executable File
291 lines
6.8 KiB
C
Executable File
/*
|
|
* 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
|
|
#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;
|
|
}
|
|
|
|
#define decompress unlzo
|