1 /* 2 * Copyright (C) 2015 The Android Open Source Project 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17 #ifndef LIBZIPARCHIVE_ZIPARCHIVECOMMON_H_ 18 #define LIBZIPARCHIVE_ZIPARCHIVECOMMON_H_ 19 20 #include "android-base/macros.h" 21 22 #include <inttypes.h> 23 24 // The "end of central directory" (EOCD) record. Each archive 25 // contains exactly once such record which appears at the end of 26 // the archive. It contains archive wide information like the 27 // number of entries in the archive and the offset to the central 28 // directory of the offset. 29 struct EocdRecord { 30 static const uint32_t kSignature = 0x06054b50; 31 32 // End of central directory signature, should always be 33 // |kSignature|. 34 uint32_t eocd_signature; 35 // The number of the current "disk", i.e, the "disk" that this 36 // central directory is on. 37 // 38 // This implementation assumes that each archive spans a single 39 // disk only. i.e, that disk_num == 1. 40 uint16_t disk_num; 41 // The disk where the central directory starts. 42 // 43 // This implementation assumes that each archive spans a single 44 // disk only. i.e, that cd_start_disk == 1. 45 uint16_t cd_start_disk; 46 // The number of central directory records on this disk. 47 // 48 // This implementation assumes that each archive spans a single 49 // disk only. i.e, that num_records_on_disk == num_records. 50 uint16_t num_records_on_disk; 51 // The total number of central directory records. 52 uint16_t num_records; 53 // The size of the central directory (in bytes). 54 uint32_t cd_size; 55 // The offset of the start of the central directory, relative 56 // to the start of the file. 57 uint32_t cd_start_offset; 58 // Length of the central directory comment. 59 uint16_t comment_length; 60 61 private: 62 EocdRecord() = default; 63 DISALLOW_COPY_AND_ASSIGN(EocdRecord); 64 } __attribute__((packed)); 65 66 // A structure representing the fixed length fields for a single 67 // record in the central directory of the archive. In addition to 68 // the fixed length fields listed here, each central directory 69 // record contains a variable length "file_name" and "extra_field" 70 // whose lengths are given by |file_name_length| and |extra_field_length| 71 // respectively. 72 struct CentralDirectoryRecord { 73 static const uint32_t kSignature = 0x02014b50; 74 75 // The start of record signature. Must be |kSignature|. 76 uint32_t record_signature; 77 // Source tool version. Top byte gives source OS. 78 uint16_t version_made_by; 79 // Tool version. Ignored by this implementation. 80 uint16_t version_needed; 81 // The "general purpose bit flags" for this entry. The only 82 // flag value that we currently check for is the "data descriptor" 83 // flag. 84 uint16_t gpb_flags; 85 // The compression method for this entry, one of |kCompressStored| 86 // and |kCompressDeflated|. 87 uint16_t compression_method; 88 // The file modification time and date for this entry. 89 uint16_t last_mod_time; 90 uint16_t last_mod_date; 91 // The CRC-32 checksum for this entry. 92 uint32_t crc32; 93 // The compressed size (in bytes) of this entry. 94 uint32_t compressed_size; 95 // The uncompressed size (in bytes) of this entry. 96 uint32_t uncompressed_size; 97 // The length of the entry file name in bytes. The file name 98 // will appear immediately after this record. 99 uint16_t file_name_length; 100 // The length of the extra field info (in bytes). This data 101 // will appear immediately after the entry file name. 102 uint16_t extra_field_length; 103 // The length of the entry comment (in bytes). This data will 104 // appear immediately after the extra field. 105 uint16_t comment_length; 106 // The start disk for this entry. Ignored by this implementation). 107 uint16_t file_start_disk; 108 // File attributes. Ignored by this implementation. 109 uint16_t internal_file_attributes; 110 // File attributes. For archives created on Unix, the top bits are the mode. 111 uint32_t external_file_attributes; 112 // The offset to the local file header for this entry, from the 113 // beginning of this archive. 114 uint32_t local_file_header_offset; 115 116 private: 117 CentralDirectoryRecord() = default; 118 DISALLOW_COPY_AND_ASSIGN(CentralDirectoryRecord); 119 } __attribute__((packed)); 120 121 // The local file header for a given entry. This duplicates information 122 // present in the central directory of the archive. It is an error for 123 // the information here to be different from the central directory 124 // information for a given entry. 125 struct LocalFileHeader { 126 static const uint32_t kSignature = 0x04034b50; 127 128 // The local file header signature, must be |kSignature|. 129 uint32_t lfh_signature; 130 // Tool version. Ignored by this implementation. 131 uint16_t version_needed; 132 // The "general purpose bit flags" for this entry. The only 133 // flag value that we currently check for is the "data descriptor" 134 // flag. 135 uint16_t gpb_flags; 136 // The compression method for this entry, one of |kCompressStored| 137 // and |kCompressDeflated|. 138 uint16_t compression_method; 139 // The file modification time and date for this entry. 140 uint16_t last_mod_time; 141 uint16_t last_mod_date; 142 // The CRC-32 checksum for this entry. 143 uint32_t crc32; 144 // The compressed size (in bytes) of this entry. 145 uint32_t compressed_size; 146 // The uncompressed size (in bytes) of this entry. 147 uint32_t uncompressed_size; 148 // The length of the entry file name in bytes. The file name 149 // will appear immediately after this record. 150 uint16_t file_name_length; 151 // The length of the extra field info (in bytes). This data 152 // will appear immediately after the entry file name. 153 uint16_t extra_field_length; 154 155 private: 156 LocalFileHeader() = default; 157 DISALLOW_COPY_AND_ASSIGN(LocalFileHeader); 158 } __attribute__((packed)); 159 160 struct DataDescriptor { 161 // The *optional* data descriptor start signature. 162 static const uint32_t kOptSignature = 0x08074b50; 163 164 // CRC-32 checksum of the entry. 165 uint32_t crc32; 166 // Compressed size of the entry. 167 uint32_t compressed_size; 168 // Uncompressed size of the entry. 169 uint32_t uncompressed_size; 170 171 private: 172 DataDescriptor() = default; 173 DISALLOW_COPY_AND_ASSIGN(DataDescriptor); 174 } __attribute__((packed)); 175 176 // mask value that signifies that the entry has a DD 177 static const uint32_t kGPBDDFlagMask = 0x0008; 178 179 // The maximum size of a central directory or a file 180 // comment in bytes. 181 static const uint32_t kMaxCommentLen = 65535; 182 183 #endif /* LIBZIPARCHIVE_ZIPARCHIVECOMMON_H_ */ 184
