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> 11889c92d2SH. Peter Anvin #include <linux/decompress/inflate.h> 12*cacb246fSAlbin Tonnerre #include <linux/decompress/unlzo.h> 13889c92d2SH. Peter Anvin 14889c92d2SH. Peter Anvin #include <linux/types.h> 15889c92d2SH. Peter Anvin #include <linux/string.h> 16889c92d2SH. Peter Anvin 1723a22d57SH. Peter Anvin #ifndef CONFIG_DECOMPRESS_GZIP 1823a22d57SH. Peter Anvin # define gunzip NULL 1923a22d57SH. Peter Anvin #endif 2023a22d57SH. Peter Anvin #ifndef CONFIG_DECOMPRESS_BZIP2 2123a22d57SH. Peter Anvin # define bunzip2 NULL 2223a22d57SH. Peter Anvin #endif 2323a22d57SH. Peter Anvin #ifndef CONFIG_DECOMPRESS_LZMA 2423a22d57SH. Peter Anvin # define unlzma NULL 2523a22d57SH. Peter Anvin #endif 26*cacb246fSAlbin Tonnerre #ifndef CONFIG_DECOMPRESS_LZO 27*cacb246fSAlbin Tonnerre # define unlzo NULL 28*cacb246fSAlbin Tonnerre #endif 2923a22d57SH. Peter Anvin 30889c92d2SH. Peter Anvin static const struct compress_format { 31889c92d2SH. Peter Anvin unsigned char magic[2]; 32889c92d2SH. Peter Anvin const char *name; 33889c92d2SH. Peter Anvin decompress_fn decompressor; 34889c92d2SH. Peter Anvin } compressed_formats[] = { 35889c92d2SH. Peter Anvin { {037, 0213}, "gzip", gunzip }, 36889c92d2SH. Peter Anvin { {037, 0236}, "gzip", gunzip }, 37889c92d2SH. Peter Anvin { {0x42, 0x5a}, "bzip2", bunzip2 }, 38889c92d2SH. Peter Anvin { {0x5d, 0x00}, "lzma", unlzma }, 39*cacb246fSAlbin Tonnerre { {0x89, 0x4c}, "lzo", unlzo }, 40889c92d2SH. Peter Anvin { {0, 0}, NULL, NULL } 41889c92d2SH. Peter Anvin }; 42889c92d2SH. Peter Anvin 43889c92d2SH. Peter Anvin decompress_fn decompress_method(const unsigned char *inbuf, int len, 44889c92d2SH. Peter Anvin const char **name) 45889c92d2SH. Peter Anvin { 46889c92d2SH. Peter Anvin const struct compress_format *cf; 47889c92d2SH. Peter Anvin 48889c92d2SH. Peter Anvin if (len < 2) 49889c92d2SH. Peter Anvin return NULL; /* Need at least this much... */ 50889c92d2SH. Peter Anvin 51e4aa7ca5SAlain Knaff for (cf = compressed_formats; cf->name; cf++) { 52889c92d2SH. Peter Anvin if (!memcmp(inbuf, cf->magic, 2)) 53889c92d2SH. Peter Anvin break; 54889c92d2SH. Peter Anvin 55889c92d2SH. Peter Anvin } 56889c92d2SH. Peter Anvin if (name) 57889c92d2SH. Peter Anvin *name = cf->name; 58889c92d2SH. Peter Anvin return cf->decompressor; 59889c92d2SH. Peter Anvin } 60