1 /* 2 * Copyright (c) 2015, 2016, Oracle and/or its affiliates. All rights reserved. 3 * 4 * Redistribution and use in source and binary forms, with or without 5 * modification, are permitted provided that the following conditions 6 * are met: 7 * 8 * - Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 11 * - Redistributions in binary form must reproduce the above copyright 12 * notice, this list of conditions and the following disclaimer in the 13 * documentation and/or other materials provided with the distribution. 14 * 15 * - Neither the name of Oracle nor the names of its 16 * contributors may be used to endorse or promote products derived 17 * from this software without specific prior written permission. 18 * 19 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS 20 * IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, 21 * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 22 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR 23 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, 24 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, 25 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR 26 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF 27 * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING 28 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS 29 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 30 */ 31 32 #ifndef LIBJIMAGE_IMAGEDECOMPRESSOR_HPP 33 #define LIBJIMAGE_IMAGEDECOMPRESSOR_HPP 34 35 #include <assert.h> 36 #include <string.h> 37 38 #include "imageFile.hpp" 39 #include "inttypes.hpp" 40 #include "jni.h" 41 42 /* 43 * Compressed resources located in image have an header. 44 * This header contains: 45 * - _magic: A magic u4, required to retrieved the header in the compressed content 46 * - _size: The size of the compressed resource. 47 * - _uncompressed_size: The uncompressed size of the compressed resource. 48 * - _decompressor_name_offset: The ImageDecompressor instance name StringsTable offset. 49 * - _decompressor_config_offset: StringsTable offset of configuration that could be needed by 50 * the decompressor in order to decompress. 51 * - _is_terminal: 1: the compressed content is terminal. Uncompressing it would 52 * create the actual resource. 0: the compressed content is not terminal. Uncompressing it 53 * will result in a compressed content to be decompressed (This occurs when a stack of compressors 54 * have been used to compress the resource. 55 */ 56 struct ResourceHeader { 57 /* magic bytes that identifies a compressed resource header*/ 58 static const u4 resource_header_magic = 0xCAFEFAFA; 59 u4 _magic; // Resource header 60 u8 _size; // Resource size 61 u8 _uncompressed_size; // Expected uncompressed size 62 u4 _decompressor_name_offset; // Strings table decompressor offset 63 u4 _decompressor_config_offset; // Strings table config offset 64 u1 _is_terminal; // Last decompressor 1, otherwise 0. 65 }; 66 67 /* 68 * Resources located in jimage file can be compressed. Compression occurs at 69 * jimage file creation time. When compressed a resource is added an header that 70 * contains the name of the compressor that compressed it. 71 * Various compression strategies can be applied to compress a resource. 72 * The same resource can even be compressed multiple time by a stack of compressors. 73 * At runtime, a resource is decompressed in a loop until there is no more header 74 * meaning that the resource is equivalent to the not compressed resource. 75 * In each iteration, the name of the compressor located in the current header 76 * is used to retrieve the associated instance of ImageDecompressor. 77 * For example "zip" is the name of the compressor that compresses resources 78 * using the zip algorithm. The ZipDecompressor class name is also "zip". 79 * ImageDecompressor instances are retrieved from a static array in which 80 * they are registered. 81 */ 82 class ImageDecompressor { 83 84 private: 85 const char* _name; 86 87 /* 88 * Array of concrete decompressors. This array is used to retrieve the decompressor 89 * that can handle resource decompression. 90 */ 91 static ImageDecompressor** _decompressors; 92 /** 93 * Num of decompressors 94 */ 95 static int _decompressors_num; 96 /* 97 * Identifier of a decompressor. This name is the identification key to retrieve 98 * decompressor from a resource header. 99 */ get_name() const100 inline const char* get_name() const { return _name; } 101 102 static u8 getU8(u1* ptr, Endian *endian); 103 static u4 getU4(u1* ptr, Endian *endian); 104 105 protected: ImageDecompressor(const char * name)106 ImageDecompressor(const char* name) : _name(name) { 107 } 108 virtual void decompress_resource(u1* data, u1* uncompressed, 109 ResourceHeader* header, const ImageStrings* strings) = 0; 110 111 public: 112 static void image_decompressor_init(); 113 static void image_decompressor_close(); 114 static ImageDecompressor* get_decompressor(const char * decompressor_name) ; 115 static void decompress_resource(u1* compressed, u1* uncompressed, 116 u8 uncompressed_size, const ImageStrings* strings, Endian* _endian); 117 }; 118 119 /** 120 * Zip decompressor. 121 */ 122 class ZipDecompressor : public ImageDecompressor { 123 public: ZipDecompressor(const char * sym)124 ZipDecompressor(const char* sym) : ImageDecompressor(sym) { } 125 void decompress_resource(u1* data, u1* uncompressed, ResourceHeader* header, 126 const ImageStrings* strings); 127 static jboolean decompress(void *in, u8 inSize, void *out, u8 outSize, char **pmsg); 128 }; 129 130 /* 131 * Shared Strings decompressor. This decompressor reconstruct the class 132 * constant pool UTF_U entries by retrieving strings stored in jimage strings table. 133 * In addition, if the UTF_8 entry is a descriptor, the descriptor has to be rebuilt, 134 * all java type having been removed from the descriptor and added to the sting table. 135 * eg: "(Ljava/lang/String;I)V" ==> "(L;I)V" and "java/lang", "String" 136 * stored in string table. offsets to the 2 strings are compressed and stored in the 137 * constantpool entry. 138 */ 139 class SharedStringDecompressor : public ImageDecompressor { 140 private: 141 // the constant pool tag for UTF8 string located in strings table 142 static const int externalized_string = 23; 143 // the constant pool tag for UTF8 descriptors string located in strings table 144 static const int externalized_string_descriptor = 25; 145 // the constant pool tag for UTF8 146 static const int constant_utf8 = 1; 147 // the constant pool tag for long 148 static const int constant_long = 5; 149 // the constant pool tag for double 150 static const int constant_double = 6; 151 // array index is the constant pool tag. value is size. 152 // eg: array[5] = 8; means size of long is 8 bytes. 153 static const u1 sizes[]; 154 // bit 5 and 6 are used to store the length of the compressed integer. 155 // size can be 1 (01), 2 (10), 3 (11). 156 // 0x60 ==> 0110000 157 static const int compressed_index_size_mask = 0x60; 158 /* 159 * mask the length bits (5 and 6) and move to the right 5 bits. 160 */ get_compressed_length(char c)161 inline static int get_compressed_length(char c) { 162 return ((char) (c & compressed_index_size_mask) >> 5); 163 } is_compressed(signed char b1)164 inline static bool is_compressed(signed char b1) { return b1 < 0; } 165 static int decompress_int(unsigned char*& value); 166 public: SharedStringDecompressor(const char * sym)167 SharedStringDecompressor(const char* sym) : ImageDecompressor(sym){} 168 void decompress_resource(u1* data, u1* uncompressed, ResourceHeader* header, 169 const ImageStrings* strings); 170 }; 171 #endif // LIBJIMAGE_IMAGEDECOMPRESSOR_HPP 172