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git.proxmox.com Git - mirror_ubuntu-artful-kernel.git/blob - lib/decompress_unlzo.c
2 * LZO decompressor for the Linux kernel. Code borrowed from the lzo
3 * implementation by Markus Franz Xaver Johannes Oberhumer.
5 * Linux kernel adaptation:
7 * Albin Tonnerre, Free Electrons <albin.tonnerre@free-electrons.com>
10 * Copyright (C) 1996-2005 Markus Franz Xaver Johannes Oberhumer
11 * All Rights Reserved.
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.
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.
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.
28 * Markus F.X.J. Oberhumer
29 * <markus@oberhumer.com>
30 * http://www.oberhumer.com/opensource/lzop/
34 #include "lzo/lzo1x_decompress.c"
36 #include <linux/decompress/unlzo.h>
39 #include <linux/types.h>
40 #include <linux/lzo.h>
41 #include <linux/decompress/mm.h>
43 #include <linux/compiler.h>
44 #include <asm/unaligned.h>
46 static const unsigned char lzop_magic
[] = {
47 0x89, 0x4c, 0x5a, 0x4f, 0x00, 0x0d, 0x0a, 0x1a, 0x0a };
49 #define LZO_BLOCK_SIZE (256*1024l)
50 #define HEADER_HAS_FILTER 0x00000800L
52 STATIC
inline int INIT
parse_header(u8
*input
, u8
*skip
)
59 /* read magic: 9 first bits */
60 for (l
= 0; l
< 9; l
++) {
61 if (*parse
++ != lzop_magic
[l
])
64 /* get version (2bytes), skip library version (2),
65 * 'need to be extracted' version (2) and
67 version
= get_unaligned_be16(parse
);
69 if (version
>= 0x0940)
71 if (get_unaligned_be32(parse
) & HEADER_HAS_FILTER
)
72 parse
+= 8; /* flags + filter info */
74 parse
+= 4; /* flags */
76 /* skip mode and mtime_low */
78 if (version
>= 0x0940)
79 parse
+= 4; /* skip mtime_high */
82 /* don't care about the file name, and skip checksum */
85 *skip
= parse
- input
;
89 STATIC
inline int INIT
unlzo(u8
*input
, int in_len
,
90 int (*fill
) (void *, unsigned int),
91 int (*flush
) (void *, unsigned int),
92 u8
*output
, int *posp
,
93 void (*error
) (char *x
))
98 u8
*in_buf
, *in_buf_save
, *out_buf
;
104 error("NULL output pointer and no flush function provided");
107 out_buf
= malloc(LZO_BLOCK_SIZE
);
109 error("Could not allocate output buffer");
115 error("Both input pointer and fill function provided, don't know what to do");
119 } else if (!fill
|| !posp
) {
120 error("NULL input pointer and missing position pointer or fill function");
123 in_buf
= malloc(lzo1x_worst_compress(LZO_BLOCK_SIZE
));
125 error("Could not allocate input buffer");
129 in_buf_save
= in_buf
;
135 fill(in_buf
, lzo1x_worst_compress(LZO_BLOCK_SIZE
));
137 if (!parse_header(input
, &skip
)) {
138 error("invalid header");
147 /* read uncompressed block size */
148 dst_len
= get_unaligned_be32(in_buf
);
151 /* exit if last block */
158 if (dst_len
> LZO_BLOCK_SIZE
) {
159 error("dest len longer than block size");
163 /* read compressed block size, and skip block checksum info */
164 src_len
= get_unaligned_be32(in_buf
);
167 if (src_len
<= 0 || src_len
> dst_len
) {
168 error("file corrupted");
175 /* When the input data is not compressed at all,
176 * lzo1x_decompress_safe will fail, so call memcpy()
178 if (unlikely(dst_len
== src_len
))
179 memcpy(out_buf
, in_buf
, src_len
);
181 r
= lzo1x_decompress_safe((u8
*) in_buf
, src_len
,
184 if (r
!= LZO_E_OK
|| dst_len
!= tmp
) {
185 error("Compressed data violation");
190 if (flush
&& flush(out_buf
, dst_len
) != dst_len
)
195 *posp
+= src_len
+ 12;
197 in_buf
= in_buf_save
;
198 fill(in_buf
, lzo1x_worst_compress(LZO_BLOCK_SIZE
));
214 #define decompress unlzo