Commit | Line | Data |
---|---|---|
889c92d2 PA |
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/inflate.h> | |
12 | ||
13 | #include <linux/types.h> | |
14 | #include <linux/string.h> | |
15 | ||
23a22d57 PA |
16 | #ifndef CONFIG_DECOMPRESS_GZIP |
17 | # define gunzip NULL | |
18 | #endif | |
19 | #ifndef CONFIG_DECOMPRESS_BZIP2 | |
20 | # define bunzip2 NULL | |
21 | #endif | |
22 | #ifndef CONFIG_DECOMPRESS_LZMA | |
23 | # define unlzma NULL | |
24 | #endif | |
25 | ||
889c92d2 PA |
26 | static const struct compress_format { |
27 | unsigned char magic[2]; | |
28 | const char *name; | |
29 | decompress_fn decompressor; | |
30 | } compressed_formats[] = { | |
889c92d2 PA |
31 | { {037, 0213}, "gzip", gunzip }, |
32 | { {037, 0236}, "gzip", gunzip }, | |
889c92d2 | 33 | { {0x42, 0x5a}, "bzip2", bunzip2 }, |
889c92d2 | 34 | { {0x5d, 0x00}, "lzma", unlzma }, |
889c92d2 PA |
35 | { {0, 0}, NULL, NULL } |
36 | }; | |
37 | ||
38 | decompress_fn decompress_method(const unsigned char *inbuf, int len, | |
39 | const char **name) | |
40 | { | |
41 | const struct compress_format *cf; | |
42 | ||
43 | if (len < 2) | |
44 | return NULL; /* Need at least this much... */ | |
45 | ||
e4aa7ca5 | 46 | for (cf = compressed_formats; cf->name; cf++) { |
889c92d2 PA |
47 | if (!memcmp(inbuf, cf->magic, 2)) |
48 | break; | |
49 | ||
50 | } | |
51 | if (name) | |
52 | *name = cf->name; | |
53 | return cf->decompressor; | |
54 | } |