blob: 31a8042772820d695b85dc15edfb33f57666b0db [file] [log] [blame]
H. Peter Anvin889c92d2009-01-08 15:14:17 -08001/*
2 * decompress.c
3 *
4 * Detect the decompression method based on magic number
5 */
6
7#include <linux/decompress/generic.h>
8
9#include <linux/decompress/bunzip2.h>
10#include <linux/decompress/unlzma.h>
Lasse Collin3ebe1242011-01-12 17:01:23 -080011#include <linux/decompress/unxz.h>
H. Peter Anvin889c92d2009-01-08 15:14:17 -080012#include <linux/decompress/inflate.h>
Albin Tonnerrecacb2462010-01-08 14:42:46 -080013#include <linux/decompress/unlzo.h>
H. Peter Anvin889c92d2009-01-08 15:14:17 -080014
15#include <linux/types.h>
16#include <linux/string.h>
Hein Tibosch33e2a422012-10-04 17:16:58 -070017#include <linux/init.h>
H. Peter Anvin889c92d2009-01-08 15:14:17 -080018
H. Peter Anvin23a22d52009-01-12 14:24:04 -080019#ifndef CONFIG_DECOMPRESS_GZIP
20# define gunzip NULL
21#endif
22#ifndef CONFIG_DECOMPRESS_BZIP2
23# define bunzip2 NULL
24#endif
25#ifndef CONFIG_DECOMPRESS_LZMA
26# define unlzma NULL
27#endif
Lasse Collin3ebe1242011-01-12 17:01:23 -080028#ifndef CONFIG_DECOMPRESS_XZ
29# define unxz NULL
30#endif
Albin Tonnerrecacb2462010-01-08 14:42:46 -080031#ifndef CONFIG_DECOMPRESS_LZO
32# define unlzo NULL
33#endif
H. Peter Anvin23a22d52009-01-12 14:24:04 -080034
Hein Tibosch33e2a422012-10-04 17:16:58 -070035struct compress_format {
H. Peter Anvin889c92d2009-01-08 15:14:17 -080036 unsigned char magic[2];
37 const char *name;
38 decompress_fn decompressor;
Hein Tibosch33e2a422012-10-04 17:16:58 -070039};
40
41static const struct compress_format compressed_formats[] __initdata = {
H. Peter Anvin889c92d2009-01-08 15:14:17 -080042 { {037, 0213}, "gzip", gunzip },
43 { {037, 0236}, "gzip", gunzip },
H. Peter Anvin889c92d2009-01-08 15:14:17 -080044 { {0x42, 0x5a}, "bzip2", bunzip2 },
H. Peter Anvin889c92d2009-01-08 15:14:17 -080045 { {0x5d, 0x00}, "lzma", unlzma },
Lasse Collin3ebe1242011-01-12 17:01:23 -080046 { {0xfd, 0x37}, "xz", unxz },
Albin Tonnerrecacb2462010-01-08 14:42:46 -080047 { {0x89, 0x4c}, "lzo", unlzo },
H. Peter Anvin889c92d2009-01-08 15:14:17 -080048 { {0, 0}, NULL, NULL }
49};
50
Hein Tibosch33e2a422012-10-04 17:16:58 -070051decompress_fn __init decompress_method(const unsigned char *inbuf, int len,
H. Peter Anvin889c92d2009-01-08 15:14:17 -080052 const char **name)
53{
54 const struct compress_format *cf;
55
56 if (len < 2)
57 return NULL; /* Need at least this much... */
58
Alain Knaffe4aa7ca2009-02-19 13:36:55 -080059 for (cf = compressed_formats; cf->name; cf++) {
H. Peter Anvin889c92d2009-01-08 15:14:17 -080060 if (!memcmp(inbuf, cf->magic, 2))
61 break;
62
63 }
64 if (name)
65 *name = cf->name;
66 return cf->decompressor;
67}