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/*
* decompress.c
*
* Detect the decompression method based on magic number
*/
#include <linux/decompress/generic.h>
#include <linux/decompress/bunzip2.h>
#include <linux/decompress/unlzma.h>
#include <linux/decompress/inflate.h>
#include <linux/types.h>
#include <linux/string.h>
#ifndef CONFIG_DECOMPRESS_GZIP
# define gunzip NULL
#endif
#ifndef CONFIG_DECOMPRESS_BZIP2
# define bunzip2 NULL
#endif
#ifndef CONFIG_DECOMPRESS_LZMA
# define unlzma NULL
#endif
static const struct compress_format {
unsigned char magic[2];
const char *name;
decompress_fn decompressor;
} compressed_formats[] = {
{ {037, 0213}, "gzip", gunzip },
{ {037, 0236}, "gzip", gunzip },
{ {0x42, 0x5a}, "bzip2", bunzip2 },
{ {0x5d, 0x00}, "lzma", unlzma },
{ {0, 0}, NULL, NULL }
};
decompress_fn decompress_method(const unsigned char *inbuf, int len,
const char **name)
{
const struct compress_format *cf;
if (len < 2)
return NULL; /* Need at least this much... */
for (cf = compressed_formats; cf->decompressor; cf++) {
if (!memcmp(inbuf, cf->magic, 2))
break;
}
if (name)
*name = cf->name;
return cf->decompressor;
}
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