[deliverable/linux.git] / lib / decompress.c

/*
 * 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/unxz.h>
#include <linux/decompress/inflate.h>
#include <linux/decompress/unlzo.h>

#include <linux/types.h>
#include <linux/string.h>
#include <linux/init.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
#ifndef CONFIG_DECOMPRESS_XZ
# define unxz NULL
#endif
#ifndef CONFIG_DECOMPRESS_LZO
# define unlzo NULL
#endif

struct compress_format {
	unsigned char magic[2];
	const char *name;
	decompress_fn decompressor;
};

static const struct compress_format compressed_formats[] __initdata = {
	{ {037, 0213}, "gzip", gunzip },
	{ {037, 0236}, "gzip", gunzip },
	{ {0x42, 0x5a}, "bzip2", bunzip2 },
	{ {0x5d, 0x00}, "lzma", unlzma },
	{ {0xfd, 0x37}, "xz", unxz },
	{ {0x89, 0x4c}, "lzo", unlzo },
	{ {0, 0}, NULL, NULL }
};

decompress_fn __init 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->name; cf++) {
		if (!memcmp(inbuf, cf->magic, 2))
			break;

	}
	if (name)
		*name = cf->name;
	return cf->decompressor;
}
Commit	Line	Data
	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/unxz.h>
	12	#include <linux/decompress/inflate.h>
	13	#include <linux/decompress/unlzo.h>
	14
	15	#include <linux/types.h>
	16	#include <linux/string.h>
	17	#include <linux/init.h>
	18
	19	#ifndef CONFIG_DECOMPRESS_GZIP
	20	# define gunzip NULL
	21	#endif
	22	#ifndef CONFIG_DECOMPRESS_BZIP2
	23	# define bunzip2 NULL
	24	#endif
	25	#ifndef CONFIG_DECOMPRESS_LZMA
	26	# define unlzma NULL
	27	#endif
	28	#ifndef CONFIG_DECOMPRESS_XZ
	29	# define unxz NULL
	30	#endif
	31	#ifndef CONFIG_DECOMPRESS_LZO
	32	# define unlzo NULL
	33	#endif
	34
	35	struct compress_format {
	36	unsigned char magic[2];
	37	const char *name;
	38	decompress_fn decompressor;
	39	};
	40
	41	static const struct compress_format compressed_formats[] __initdata = {
	42	{ {037, 0213}, "gzip", gunzip },
	43	{ {037, 0236}, "gzip", gunzip },
	44	{ {0x42, 0x5a}, "bzip2", bunzip2 },
	45	{ {0x5d, 0x00}, "lzma", unlzma },
	46	{ {0xfd, 0x37}, "xz", unxz },
	47	{ {0x89, 0x4c}, "lzo", unlzo },
	48	{ {0, 0}, NULL, NULL }
	49	};
	50
	51	decompress_fn __init decompress_method(const unsigned char *inbuf, int len,
	52	const char **name)
	53	{
	54	const struct compress_format *cf;
	55
	56	if (len < 2)
	57	return NULL; /* Need at least this much... */
	58
	59	for (cf = compressed_formats; cf->name; cf++) {
	60	if (!memcmp(inbuf, cf->magic, 2))
	61	break;
	62
	63	}
	64	if (name)
	65	*name = cf->name;
	66	return cf->decompressor;
	67	}