1 /* 2 * Squashfs - a compressed read only filesystem for Linux 3 * 4 * Copyright (c) 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009 5 * Phillip Lougher <phillip@lougher.demon.co.uk> 6 * 7 * This program is free software; you can redistribute it and/or 8 * modify it under the terms of the GNU General Public License 9 * as published by the Free Software Foundation; either version 2, 10 * or (at your option) any later version. 11 * 12 * This program is distributed in the hope that it will be useful, 13 * but WITHOUT ANY WARRANTY; without even the implied warranty of 14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 15 * GNU General Public License for more details. 16 * 17 * You should have received a copy of the GNU General Public License 18 * along with this program; if not, write to the Free Software 19 * Foundation, 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. 20 * 21 * decompressor.c 22 */ 23 24 #include <linux/types.h> 25 #include <linux/mutex.h> 26 #include <linux/buffer_head.h> 27 28 #include "squashfs_fs.h" 29 #include "squashfs_fs_sb.h" 30 #include "decompressor.h" 31 #include "squashfs.h" 32 33 /* 34 * This file (and decompressor.h) implements a decompressor framework for 35 * Squashfs, allowing multiple decompressors to be easily supported 36 */ 37 38 static const struct squashfs_decompressor squashfs_lzma_unsupported_comp_ops = { 39 NULL, NULL, NULL, LZMA_COMPRESSION, "lzma", 0 40 }; 41 42 #ifndef CONFIG_SQUASHFS_LZO 43 static const struct squashfs_decompressor squashfs_lzo_comp_ops = { 44 NULL, NULL, NULL, LZO_COMPRESSION, "lzo", 0 45 }; 46 #endif 47 48 #ifndef CONFIG_SQUASHFS_XZ 49 static const struct squashfs_decompressor squashfs_xz_comp_ops = { 50 NULL, NULL, NULL, XZ_COMPRESSION, "xz", 0 51 }; 52 #endif 53 54 static const struct squashfs_decompressor squashfs_unknown_comp_ops = { 55 NULL, NULL, NULL, 0, "unknown", 0 56 }; 57 58 static const struct squashfs_decompressor *decompressor[] = { 59 &squashfs_zlib_comp_ops, 60 &squashfs_lzo_comp_ops, 61 &squashfs_xz_comp_ops, 62 &squashfs_lzma_unsupported_comp_ops, 63 &squashfs_unknown_comp_ops 64 }; 65 66 67 const struct squashfs_decompressor *squashfs_lookup_decompressor(int id) 68 { 69 int i; 70 71 for (i = 0; decompressor[i]->id; i++) 72 if (id == decompressor[i]->id) 73 break; 74 75 return decompressor[i]; 76 } 77