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#include <linux/decompress/unlz4.h>
15
16#include <linux/types.h>
17#include <linux/string.h>
18#include <linux/init.h>
19#include <linux/printk.h>
20
21#ifndef CONFIG_DECOMPRESS_GZIP
22# define gunzip NULL
23#endif
24#ifndef CONFIG_DECOMPRESS_BZIP2
25# define bunzip2 NULL
26#endif
27#ifndef CONFIG_DECOMPRESS_LZMA
28# define unlzma NULL
29#endif
30#ifndef CONFIG_DECOMPRESS_XZ
31# define unxz NULL
32#endif
33#ifndef CONFIG_DECOMPRESS_LZO
34# define unlzo NULL
35#endif
36#ifndef CONFIG_DECOMPRESS_LZ4
37# define unlz4 NULL
38#endif
39
40struct compress_format {
41	unsigned char magic[2];
42	const char *name;
43	decompress_fn decompressor;
44};
45
46static const struct compress_format compressed_formats[] __initconst = {
47	{ {037, 0213}, "gzip", gunzip },
48	{ {037, 0236}, "gzip", gunzip },
49	{ {0x42, 0x5a}, "bzip2", bunzip2 },
50	{ {0x5d, 0x00}, "lzma", unlzma },
51	{ {0xfd, 0x37}, "xz", unxz },
52	{ {0x89, 0x4c}, "lzo", unlzo },
53	{ {0x02, 0x21}, "lz4", unlz4 },
54	{ {0, 0}, NULL, NULL }
55};
56
57decompress_fn __init decompress_method(const unsigned char *inbuf, int len,
58				const char **name)
59{
60	const struct compress_format *cf;
61
62	if (len < 2)
63		return NULL;	/* Need at least this much... */
64
65	pr_debug("Compressed data magic: %#.2x %#.2x\n", inbuf[0], inbuf[1]);
66
67	for (cf = compressed_formats; cf->name; cf++) {
68		if (!memcmp(inbuf, cf->magic, 2))
69			break;
70
71	}
72	if (name)
73		*name = cf->name;
74	return cf->decompressor;
75}

 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
18#ifndef CONFIG_DECOMPRESS_GZIP
19# define gunzip NULL
20#endif
21#ifndef CONFIG_DECOMPRESS_BZIP2
22# define bunzip2 NULL
23#endif
24#ifndef CONFIG_DECOMPRESS_LZMA
25# define unlzma NULL
26#endif
27#ifndef CONFIG_DECOMPRESS_XZ
28# define unxz NULL
29#endif
30#ifndef CONFIG_DECOMPRESS_LZO
31# define unlzo NULL
32#endif
 
 
 
33
34static const struct compress_format {
35	unsigned char magic[2];
36	const char *name;
37	decompress_fn decompressor;
38} compressed_formats[] = {
 
 
39	{ {037, 0213}, "gzip", gunzip },
40	{ {037, 0236}, "gzip", gunzip },
41	{ {0x42, 0x5a}, "bzip2", bunzip2 },
42	{ {0x5d, 0x00}, "lzma", unlzma },
43	{ {0xfd, 0x37}, "xz", unxz },
44	{ {0x89, 0x4c}, "lzo", unlzo },
 
45	{ {0, 0}, NULL, NULL }
46};
47
48decompress_fn decompress_method(const unsigned char *inbuf, int len,
49				const char **name)
50{
51	const struct compress_format *cf;
52
53	if (len < 2)
54		return NULL;	/* Need at least this much... */
 
 
55
56	for (cf = compressed_formats; cf->name; cf++) {
57		if (!memcmp(inbuf, cf->magic, 2))
58			break;
59
60	}
61	if (name)
62		*name = cf->name;
63	return cf->decompressor;
64}