Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
tjh.dev
kernel
os
linux
1/*
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>
11#include <linux/decompress/unxz.h>
12#include <linux/decompress/inflate.h>
13#include <linux/decompress/unlzo.h>
14
15#include <linux/types.h>
16#include <linux/string.h>
17#include <linux/init.h>
18
19#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
28#ifndef CONFIG_DECOMPRESS_XZ
29# define unxz NULL
30#endif
31#ifndef CONFIG_DECOMPRESS_LZO
32# define unlzo NULL
33#endif
34
35struct compress_format {
36 unsigned char magic[2];
37 const char *name;
38 decompress_fn decompressor;
39};
40
41static const struct compress_format compressed_formats[] __initdata = {
42 { {037, 0213}, "gzip", gunzip },
43 { {037, 0236}, "gzip", gunzip },
44 { {0x42, 0x5a}, "bzip2", bunzip2 },
45 { {0x5d, 0x00}, "lzma", unlzma },
46 { {0xfd, 0x37}, "xz", unxz },
47 { {0x89, 0x4c}, "lzo", unlzo },
48 { {0, 0}, NULL, NULL }
49};
50
51decompress_fn __init decompress_method(const unsigned char *inbuf, int len,
52 const char **name)
53{
54 const struct compress_format *cf;
55
56 if (len < 2)
57 return NULL; /* Need at least this much... */
58
59 for (cf = compressed_formats; cf->name; cf++) {
60 if (!memcmp(inbuf, cf->magic, 2))
61 break;
62
63 }
64 if (name)
65 *name = cf->name;
66 return cf->decompressor;
67}