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/*
* Copyright (C) 2015 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#ifndef LIBZIPARCHIVE_ZIPARCHIVECOMMON_H_
#define LIBZIPARCHIVE_ZIPARCHIVECOMMON_H_
#include "android-base/macros.h"
#include <inttypes.h>
// The "end of central directory" (EOCD) record. Each archive
// contains exactly once such record which appears at the end of
// the archive. It contains archive wide information like the
// number of entries in the archive and the offset to the central
// directory of the offset.
struct EocdRecord {
static const uint32_t kSignature = 0x06054b50;
// End of central directory signature, should always be
// |kSignature|.
uint32_t eocd_signature;
// The number of the current "disk", i.e, the "disk" that this
// central directory is on.
//
// This implementation assumes that each archive spans a single
// disk only. i.e, that disk_num == 1.
uint16_t disk_num;
// The disk where the central directory starts.
//
// This implementation assumes that each archive spans a single
// disk only. i.e, that cd_start_disk == 1.
uint16_t cd_start_disk;
// The number of central directory records on this disk.
//
// This implementation assumes that each archive spans a single
// disk only. i.e, that num_records_on_disk == num_records.
uint16_t num_records_on_disk;
// The total number of central directory records.
uint16_t num_records;
// The size of the central directory (in bytes).
uint32_t cd_size;
// The offset of the start of the central directory, relative
// to the start of the file.
uint32_t cd_start_offset;
// Length of the central directory comment.
uint16_t comment_length;
private:
EocdRecord() = default;
DISALLOW_COPY_AND_ASSIGN(EocdRecord);
} __attribute__((packed));
// A structure representing the fixed length fields for a single
// record in the central directory of the archive. In addition to
// the fixed length fields listed here, each central directory
// record contains a variable length "file_name" and "extra_field"
// whose lengths are given by |file_name_length| and |extra_field_length|
// respectively.
struct CentralDirectoryRecord {
static const uint32_t kSignature = 0x02014b50;
// The start of record signature. Must be |kSignature|.
uint32_t record_signature;
// Source tool version. Top byte gives source OS.
uint16_t version_made_by;
// Tool version. Ignored by this implementation.
uint16_t version_needed;
// The "general purpose bit flags" for this entry. The only
// flag value that we currently check for is the "data descriptor"
// flag.
uint16_t gpb_flags;
// The compression method for this entry, one of |kCompressStored|
// and |kCompressDeflated|.
uint16_t compression_method;
// The file modification time and date for this entry.
uint16_t last_mod_time;
uint16_t last_mod_date;
// The CRC-32 checksum for this entry.
uint32_t crc32;
// The compressed size (in bytes) of this entry.
uint32_t compressed_size;
// The uncompressed size (in bytes) of this entry.
uint32_t uncompressed_size;
// The length of the entry file name in bytes. The file name
// will appear immediately after this record.
uint16_t file_name_length;
// The length of the extra field info (in bytes). This data
// will appear immediately after the entry file name.
uint16_t extra_field_length;
// The length of the entry comment (in bytes). This data will
// appear immediately after the extra field.
uint16_t comment_length;
// The start disk for this entry. Ignored by this implementation).
uint16_t file_start_disk;
// File attributes. Ignored by this implementation.
uint16_t internal_file_attributes;
// File attributes. For archives created on Unix, the top bits are the mode.
uint32_t external_file_attributes;
// The offset to the local file header for this entry, from the
// beginning of this archive.
uint32_t local_file_header_offset;
private:
CentralDirectoryRecord() = default;
DISALLOW_COPY_AND_ASSIGN(CentralDirectoryRecord);
} __attribute__((packed));
// The local file header for a given entry. This duplicates information
// present in the central directory of the archive. It is an error for
// the information here to be different from the central directory
// information for a given entry.
struct LocalFileHeader {
static const uint32_t kSignature = 0x04034b50;
// The local file header signature, must be |kSignature|.
uint32_t lfh_signature;
// Tool version. Ignored by this implementation.
uint16_t version_needed;
// The "general purpose bit flags" for this entry. The only
// flag value that we currently check for is the "data descriptor"
// flag.
uint16_t gpb_flags;
// The compression method for this entry, one of |kCompressStored|
// and |kCompressDeflated|.
uint16_t compression_method;
// The file modification time and date for this entry.
uint16_t last_mod_time;
uint16_t last_mod_date;
// The CRC-32 checksum for this entry.
uint32_t crc32;
// The compressed size (in bytes) of this entry.
uint32_t compressed_size;
// The uncompressed size (in bytes) of this entry.
uint32_t uncompressed_size;
// The length of the entry file name in bytes. The file name
// will appear immediately after this record.
uint16_t file_name_length;
// The length of the extra field info (in bytes). This data
// will appear immediately after the entry file name.
uint16_t extra_field_length;
private:
LocalFileHeader() = default;
DISALLOW_COPY_AND_ASSIGN(LocalFileHeader);
} __attribute__((packed));
struct DataDescriptor {
// The *optional* data descriptor start signature.
static const uint32_t kOptSignature = 0x08074b50;
// CRC-32 checksum of the entry.
uint32_t crc32;
// Compressed size of the entry.
uint32_t compressed_size;
// Uncompressed size of the entry.
uint32_t uncompressed_size;
private:
DataDescriptor() = default;
DISALLOW_COPY_AND_ASSIGN(DataDescriptor);
} __attribute__((packed));
// mask value that signifies that the entry has a DD
static const uint32_t kGPBDDFlagMask = 0x0008;
// The maximum size of a central directory or a file
// comment in bytes.
static const uint32_t kMaxCommentLen = 65535;
#endif /* LIBZIPARCHIVE_ZIPARCHIVECOMMON_H_ */