projects / linux.git / blame
| 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> | |
| cacb246f | 12 | #include <linux/decompress/unlzo.h> |
| 889c92d2 PA |
13 | |
| 14 | #include <linux/types.h> | |
| 15 | #include <linux/string.h> | |
| 16 | ||
| 23a22d57 PA |
17 | #ifndef CONFIG_DECOMPRESS_GZIP |
| 18 | # define gunzip NULL | |
| 19 | #endif | |
| 20 | #ifndef CONFIG_DECOMPRESS_BZIP2 | |
| 21 | # define bunzip2 NULL | |
| 22 | #endif | |
| 23 | #ifndef CONFIG_DECOMPRESS_LZMA | |
| 24 | # define unlzma NULL | |
| 25 | #endif | |
| cacb246f AT |
26 | #ifndef CONFIG_DECOMPRESS_LZO |
| 27 | # define unlzo NULL | |
| 28 | #endif | |
| 23a22d57 | 29 | |
| 889c92d2 PA |
30 | static const struct compress_format { |
| 31 | unsigned char magic[2]; | |
| 32 | const char *name; | |
| 33 | decompress_fn decompressor; | |
| 34 | } compressed_formats[] = { | |
| 889c92d2 PA |
35 | { {037, 0213}, "gzip", gunzip }, |
| 36 | { {037, 0236}, "gzip", gunzip }, | |
| 889c92d2 | 37 | { {0x42, 0x5a}, "bzip2", bunzip2 }, |
| 889c92d2 | 38 | { {0x5d, 0x00}, "lzma", unlzma }, |
| cacb246f | 39 | { {0x89, 0x4c}, "lzo", unlzo }, |
| 889c92d2 PA |
40 | { {0, 0}, NULL, NULL } |
| 41 | }; | |
| 42 | ||
| 43 | decompress_fn decompress_method(const unsigned char *inbuf, int len, | |
| 44 | const char **name) | |
| 45 | { | |
| 46 | const struct compress_format *cf; | |
| 47 | ||
| 48 | if (len < 2) | |
| 49 | return NULL; /* Need at least this much... */ | |
| 50 | ||
| e4aa7ca5 | 51 | for (cf = compressed_formats; cf->name; cf++) { |
| 889c92d2 PA |
52 | if (!memcmp(inbuf, cf->magic, 2)) |
| 53 | break; | |
| 54 | ||
| 55 | } | |
| 56 | if (name) | |
| 57 | *name = cf->name; | |
| 58 | return cf->decompressor; | |
| 59 | } |