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> | |
| 3ebe1243 | 11 | #include <linux/decompress/unxz.h> |
| 889c92d2 | 12 | #include <linux/decompress/inflate.h> |
| cacb246f | 13 | #include <linux/decompress/unlzo.h> |
| e76e1fdf | 14 | #include <linux/decompress/unlz4.h> |
| 889c92d2 PA |
15 | |
| 16 | #include <linux/types.h> | |
| 17 | #include <linux/string.h> | |
| 33e2a422 | 18 | #include <linux/init.h> |
| 6aa7a29a | 19 | #include <linux/printk.h> |
| 889c92d2 | 20 | |
| 23a22d57 PA |
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 | |
| 3ebe1243 LC |
30 | #ifndef CONFIG_DECOMPRESS_XZ |
| 31 | # define unxz NULL | |
| 32 | #endif | |
| cacb246f AT |
33 | #ifndef CONFIG_DECOMPRESS_LZO |
| 34 | # define unlzo NULL | |
| 35 | #endif | |
| e76e1fdf KL |
36 | #ifndef CONFIG_DECOMPRESS_LZ4 |
| 37 | # define unlz4 NULL | |
| 38 | #endif | |
| 23a22d57 | 39 | |
| 33e2a422 | 40 | struct compress_format { |
| 889c92d2 PA |
41 | unsigned char magic[2]; |
| 42 | const char *name; | |
| 43 | decompress_fn decompressor; | |
| 33e2a422 HT |
44 | }; |
| 45 | ||
| 6f9982bd | 46 | static const struct compress_format compressed_formats[] __initconst = { |
| a060bfe0 HK |
47 | { {0x1f, 0x8b}, "gzip", gunzip }, |
| 48 | { {0x1f, 0x9e}, "gzip", gunzip }, | |
| 889c92d2 | 49 | { {0x42, 0x5a}, "bzip2", bunzip2 }, |
| 889c92d2 | 50 | { {0x5d, 0x00}, "lzma", unlzma }, |
| 3ebe1243 | 51 | { {0xfd, 0x37}, "xz", unxz }, |
| cacb246f | 52 | { {0x89, 0x4c}, "lzo", unlzo }, |
| e76e1fdf | 53 | { {0x02, 0x21}, "lz4", unlz4 }, |
| 889c92d2 PA |
54 | { {0, 0}, NULL, NULL } |
| 55 | }; | |
| 56 | ||
| d97b07c5 | 57 | decompress_fn __init decompress_method(const unsigned char *inbuf, long len, |
| 889c92d2 PA |
58 | const char **name) |
| 59 | { | |
| 60 | const struct compress_format *cf; | |
| 61 | ||
| 5a09e6ce AK |
62 | if (len < 2) { |
| 63 | if (name) | |
| 64 | *name = NULL; | |
| 889c92d2 | 65 | return NULL; /* Need at least this much... */ |
| 5a09e6ce | 66 | } |
| 889c92d2 | 67 | |
| 6aa7a29a DW |
68 | pr_debug("Compressed data magic: %#.2x %#.2x\n", inbuf[0], inbuf[1]); |
| 69 | ||
| e4aa7ca5 | 70 | for (cf = compressed_formats; cf->name; cf++) { |
| 889c92d2 PA |
71 | if (!memcmp(inbuf, cf->magic, 2)) |
| 72 | break; | |
| 73 | ||
| 74 | } | |
| 75 | if (name) | |
| 76 | *name = cf->name; | |
| 77 | return cf->decompressor; | |
| 78 | } |