git://bbs.cooldavid.org / net-next-2.6.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> | |
| 12 | ||
| 13 | #include <linux/types.h> | |
| 14 | #include <linux/string.h> | |
| 15 | ||
| 16 | static const struct compress_format { | |
| 17 | unsigned char magic[2]; | |
| 18 | const char *name; | |
| 19 | decompress_fn decompressor; | |
| 20 | } compressed_formats[] = { | |
| 21 | #ifdef CONFIG_DECOMPRESS_GZIP | |
| 22 | { {037, 0213}, "gzip", gunzip }, | |
| 23 | { {037, 0236}, "gzip", gunzip }, | |
| 24 | #endif | |
| 25 | #ifdef CONFIG_DECOMPRESS_BZIP2 | |
| 26 | { {0x42, 0x5a}, "bzip2", bunzip2 }, | |
| 27 | #endif | |
| 28 | #ifdef CONFIG_DECOMPRESS_LZMA | |
| 29 | { {0x5d, 0x00}, "lzma", unlzma }, | |
| 30 | #endif | |
| 31 | { {0, 0}, NULL, NULL } | |
| 32 | }; | |
| 33 | ||
| 34 | decompress_fn decompress_method(const unsigned char *inbuf, int len, | |
| 35 | const char **name) | |
| 36 | { | |
| 37 | const struct compress_format *cf; | |
| 38 | ||
| 39 | if (len < 2) | |
| 40 | return NULL; /* Need at least this much... */ | |
| 41 | ||
| 42 | for (cf = compressed_formats; cf->decompressor; cf++) { | |
| 43 | if (!memcmp(inbuf, cf->magic, 2)) | |
| 44 | break; | |
| 45 | ||
| 46 | } | |
| 47 | if (name) | |
| 48 | *name = cf->name; | |
| 49 | return cf->decompressor; | |
| 50 | } |