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> 11*3ebe1243SLasse Collin #include <linux/decompress/unxz.h> 12889c92d2SH. Peter Anvin #include <linux/decompress/inflate.h> 13cacb246fSAlbin Tonnerre #include <linux/decompress/unlzo.h> 14889c92d2SH. Peter Anvin 15889c92d2SH. Peter Anvin #include <linux/types.h> 16889c92d2SH. Peter Anvin #include <linux/string.h> 17889c92d2SH. Peter Anvin 1823a22d57SH. Peter Anvin #ifndef CONFIG_DECOMPRESS_GZIP 1923a22d57SH. Peter Anvin # define gunzip NULL 2023a22d57SH. Peter Anvin #endif 2123a22d57SH. Peter Anvin #ifndef CONFIG_DECOMPRESS_BZIP2 2223a22d57SH. Peter Anvin # define bunzip2 NULL 2323a22d57SH. Peter Anvin #endif 2423a22d57SH. Peter Anvin #ifndef CONFIG_DECOMPRESS_LZMA 2523a22d57SH. Peter Anvin # define unlzma NULL 2623a22d57SH. Peter Anvin #endif 27*3ebe1243SLasse Collin #ifndef CONFIG_DECOMPRESS_XZ 28*3ebe1243SLasse Collin # define unxz NULL 29*3ebe1243SLasse Collin #endif 30cacb246fSAlbin Tonnerre #ifndef CONFIG_DECOMPRESS_LZO 31cacb246fSAlbin Tonnerre # define unlzo NULL 32cacb246fSAlbin Tonnerre #endif 3323a22d57SH. Peter Anvin 34889c92d2SH. Peter Anvin static const struct compress_format { 35889c92d2SH. Peter Anvin unsigned char magic[2]; 36889c92d2SH. Peter Anvin const char *name; 37889c92d2SH. Peter Anvin decompress_fn decompressor; 38889c92d2SH. Peter Anvin } compressed_formats[] = { 39889c92d2SH. Peter Anvin { {037, 0213}, "gzip", gunzip }, 40889c92d2SH. Peter Anvin { {037, 0236}, "gzip", gunzip }, 41889c92d2SH. Peter Anvin { {0x42, 0x5a}, "bzip2", bunzip2 }, 42889c92d2SH. Peter Anvin { {0x5d, 0x00}, "lzma", unlzma }, 43*3ebe1243SLasse Collin { {0xfd, 0x37}, "xz", unxz }, 44cacb246fSAlbin Tonnerre { {0x89, 0x4c}, "lzo", unlzo }, 45889c92d2SH. Peter Anvin { {0, 0}, NULL, NULL } 46889c92d2SH. Peter Anvin }; 47889c92d2SH. Peter Anvin 48889c92d2SH. Peter Anvin decompress_fn decompress_method(const unsigned char *inbuf, int len, 49889c92d2SH. Peter Anvin const char **name) 50889c92d2SH. Peter Anvin { 51889c92d2SH. Peter Anvin const struct compress_format *cf; 52889c92d2SH. Peter Anvin 53889c92d2SH. Peter Anvin if (len < 2) 54889c92d2SH. Peter Anvin return NULL; /* Need at least this much... */ 55889c92d2SH. Peter Anvin 56e4aa7ca5SAlain Knaff for (cf = compressed_formats; cf->name; cf++) { 57889c92d2SH. Peter Anvin if (!memcmp(inbuf, cf->magic, 2)) 58889c92d2SH. Peter Anvin break; 59889c92d2SH. Peter Anvin 60889c92d2SH. Peter Anvin } 61889c92d2SH. Peter Anvin if (name) 62889c92d2SH. Peter Anvin *name = cf->name; 63889c92d2SH. Peter Anvin return cf->decompressor; 64889c92d2SH. Peter Anvin } 65