1889c92d2SH. Peter Anvin /* 2889c92d2SH. Peter Anvin * decompress.c 3889c92d2SH. Peter Anvin * 4889c92d2SH. Peter Anvin * Detect the decompression method based on magic number 5889c92d2SH. Peter Anvin */ 6889c92d2SH. Peter Anvin 7889c92d2SH. Peter Anvin #include <linux/decompress/generic.h> 8889c92d2SH. Peter Anvin 9889c92d2SH. Peter Anvin #include <linux/decompress/bunzip2.h> 10889c92d2SH. Peter Anvin #include <linux/decompress/unlzma.h> 113ebe1243SLasse Collin #include <linux/decompress/unxz.h> 12889c92d2SH. Peter Anvin #include <linux/decompress/inflate.h> 13cacb246fSAlbin Tonnerre #include <linux/decompress/unlzo.h> 14e76e1fdfSKyungsik Lee #include <linux/decompress/unlz4.h> 15889c92d2SH. Peter Anvin 16889c92d2SH. Peter Anvin #include <linux/types.h> 17889c92d2SH. Peter Anvin #include <linux/string.h> 1833e2a422SHein Tibosch #include <linux/init.h> 19*6aa7a29aSDaniel M. Weeks #include <linux/printk.h> 20889c92d2SH. Peter Anvin 2123a22d57SH. Peter Anvin #ifndef CONFIG_DECOMPRESS_GZIP 2223a22d57SH. Peter Anvin # define gunzip NULL 2323a22d57SH. Peter Anvin #endif 2423a22d57SH. Peter Anvin #ifndef CONFIG_DECOMPRESS_BZIP2 2523a22d57SH. Peter Anvin # define bunzip2 NULL 2623a22d57SH. Peter Anvin #endif 2723a22d57SH. Peter Anvin #ifndef CONFIG_DECOMPRESS_LZMA 2823a22d57SH. Peter Anvin # define unlzma NULL 2923a22d57SH. Peter Anvin #endif 303ebe1243SLasse Collin #ifndef CONFIG_DECOMPRESS_XZ 313ebe1243SLasse Collin # define unxz NULL 323ebe1243SLasse Collin #endif 33cacb246fSAlbin Tonnerre #ifndef CONFIG_DECOMPRESS_LZO 34cacb246fSAlbin Tonnerre # define unlzo NULL 35cacb246fSAlbin Tonnerre #endif 36e76e1fdfSKyungsik Lee #ifndef CONFIG_DECOMPRESS_LZ4 37e76e1fdfSKyungsik Lee # define unlz4 NULL 38e76e1fdfSKyungsik Lee #endif 3923a22d57SH. Peter Anvin 4033e2a422SHein Tibosch struct compress_format { 41889c92d2SH. Peter Anvin unsigned char magic[2]; 42889c92d2SH. Peter Anvin const char *name; 43889c92d2SH. Peter Anvin decompress_fn decompressor; 4433e2a422SHein Tibosch }; 4533e2a422SHein Tibosch 466f9982bdSAndi Kleen static const struct compress_format compressed_formats[] __initconst = { 47889c92d2SH. Peter Anvin { {037, 0213}, "gzip", gunzip }, 48889c92d2SH. Peter Anvin { {037, 0236}, "gzip", gunzip }, 49889c92d2SH. Peter Anvin { {0x42, 0x5a}, "bzip2", bunzip2 }, 50889c92d2SH. Peter Anvin { {0x5d, 0x00}, "lzma", unlzma }, 513ebe1243SLasse Collin { {0xfd, 0x37}, "xz", unxz }, 52cacb246fSAlbin Tonnerre { {0x89, 0x4c}, "lzo", unlzo }, 53e76e1fdfSKyungsik Lee { {0x02, 0x21}, "lz4", unlz4 }, 54889c92d2SH. Peter Anvin { {0, 0}, NULL, NULL } 55889c92d2SH. Peter Anvin }; 56889c92d2SH. Peter Anvin 5733e2a422SHein Tibosch decompress_fn __init decompress_method(const unsigned char *inbuf, int len, 58889c92d2SH. Peter Anvin const char **name) 59889c92d2SH. Peter Anvin { 60889c92d2SH. Peter Anvin const struct compress_format *cf; 61889c92d2SH. Peter Anvin 62889c92d2SH. Peter Anvin if (len < 2) 63889c92d2SH. Peter Anvin return NULL; /* Need at least this much... */ 64889c92d2SH. Peter Anvin 65*6aa7a29aSDaniel M. Weeks pr_debug("Compressed data magic: %#.2x %#.2x\n", inbuf[0], inbuf[1]); 66*6aa7a29aSDaniel M. Weeks 67e4aa7ca5SAlain Knaff for (cf = compressed_formats; cf->name; cf++) { 68889c92d2SH. Peter Anvin if (!memcmp(inbuf, cf->magic, 2)) 69889c92d2SH. Peter Anvin break; 70889c92d2SH. Peter Anvin 71889c92d2SH. Peter Anvin } 72889c92d2SH. Peter Anvin if (name) 73889c92d2SH. Peter Anvin *name = cf->name; 74889c92d2SH. Peter Anvin return cf->decompressor; 75889c92d2SH. Peter Anvin } 76