linux/lib/decompress_unlzo.c
Thomas Gleixner 45a46873f0 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 95
Based on 1 normalized pattern(s):

  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

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-or-later

has been chosen to replace the boilerplate/reference in 1 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Richard Fontana <rfontana@redhat.com>
Reviewed-by: Allison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190520075212.429390570@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-24 17:37:53 +02:00

288 lines
6.4 KiB
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 <albin.tonnerre@free-electrons.com>
*
* Original code:
* Copyright (C) 1996-2005 Markus Franz Xaver Johannes Oberhumer
* All Rights Reserved.
*
* 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