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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.
*/
#include "ziparchive/zip_writer.h"
#include <cstdio>
#include <sys/param.h>
#include <sys/stat.h>
#include <zlib.h>
#define DEF_MEM_LEVEL 8 // normally in zutil.h?
#include <memory>
#include <vector>
#include "android-base/logging.h"
#include "utils/Compat.h"
#include "utils/Log.h"
#include "entry_name_utils-inl.h"
#include "zip_archive_common.h"
#if !defined(powerof2)
#define powerof2(x) ((((x)-1)&(x))==0)
#endif
/* Zip compression methods we support */
enum {
kCompressStored = 0, // no compression
kCompressDeflated = 8, // standard deflate
};
// Size of the output buffer used for compression.
static const size_t kBufSize = 32768u;
// No error, operation completed successfully.
static const int32_t kNoError = 0;
// The ZipWriter is in a bad state.
static const int32_t kInvalidState = -1;
// There was an IO error while writing to disk.
static const int32_t kIoError = -2;
// The zip entry name was invalid.
static const int32_t kInvalidEntryName = -3;
// An error occurred in zlib.
static const int32_t kZlibError = -4;
// The start aligned function was called with the aligned flag.
static const int32_t kInvalidAlign32Flag = -5;
// The alignment parameter is not a power of 2.
static const int32_t kInvalidAlignment = -6;
static const char* sErrorCodes[] = {
"Invalid state",
"IO error",
"Invalid entry name",
"Zlib error",
};
const char* ZipWriter::ErrorCodeString(int32_t error_code) {
if (error_code < 0 && (-error_code) < static_cast<int32_t>(arraysize(sErrorCodes))) {
return sErrorCodes[-error_code];
}
return nullptr;
}
static void DeleteZStream(z_stream* stream) {
deflateEnd(stream);
delete stream;
}
ZipWriter::ZipWriter(FILE* f) : file_(f), seekable_(false), current_offset_(0),
state_(State::kWritingZip), z_stream_(nullptr, DeleteZStream),
buffer_(kBufSize) {
// Check if the file is seekable (regular file). If fstat fails, that's fine, subsequent calls
// will fail as well.
struct stat file_stats;
if (fstat(fileno(f), &file_stats) == 0) {
seekable_ = S_ISREG(file_stats.st_mode);
}
}
ZipWriter::ZipWriter(ZipWriter&& writer) : file_(writer.file_),
seekable_(writer.seekable_),
current_offset_(writer.current_offset_),
state_(writer.state_),
files_(std::move(writer.files_)),
z_stream_(std::move(writer.z_stream_)),
buffer_(std::move(writer.buffer_)){
writer.file_ = nullptr;
writer.state_ = State::kError;
}
ZipWriter& ZipWriter::operator=(ZipWriter&& writer) {
file_ = writer.file_;
seekable_ = writer.seekable_;
current_offset_ = writer.current_offset_;
state_ = writer.state_;
files_ = std::move(writer.files_);
z_stream_ = std::move(writer.z_stream_);
buffer_ = std::move(writer.buffer_);
writer.file_ = nullptr;
writer.state_ = State::kError;
return *this;
}
int32_t ZipWriter::HandleError(int32_t error_code) {
state_ = State::kError;
z_stream_.reset();
return error_code;
}
int32_t ZipWriter::StartEntry(const char* path, size_t flags) {
uint32_t alignment = 0;
if (flags & kAlign32) {
flags &= ~kAlign32;
alignment = 4;
}
return StartAlignedEntryWithTime(path, flags, time_t(), alignment);
}
int32_t ZipWriter::StartAlignedEntry(const char* path, size_t flags, uint32_t alignment) {
return StartAlignedEntryWithTime(path, flags, time_t(), alignment);
}
int32_t ZipWriter::StartEntryWithTime(const char* path, size_t flags, time_t time) {
uint32_t alignment = 0;
if (flags & kAlign32) {
flags &= ~kAlign32;
alignment = 4;
}
return StartAlignedEntryWithTime(path, flags, time, alignment);
}
static void ExtractTimeAndDate(time_t when, uint16_t* out_time, uint16_t* out_date) {
/* round up to an even number of seconds */
when = static_cast<time_t>((static_cast<unsigned long>(when) + 1) & (~1));
struct tm* ptm;
#if !defined(_WIN32)
struct tm tm_result;
ptm = localtime_r(&when, &tm_result);
#else
ptm = localtime(&when);
#endif
int year = ptm->tm_year;
if (year < 80) {
year = 80;
}
*out_date = (year - 80) << 9 | (ptm->tm_mon + 1) << 5 | ptm->tm_mday;
*out_time = ptm->tm_hour << 11 | ptm->tm_min << 5 | ptm->tm_sec >> 1;
}
static void CopyFromFileEntry(const ZipWriter::FileEntry& src, bool use_data_descriptor,
LocalFileHeader* dst) {
dst->lfh_signature = LocalFileHeader::kSignature;
if (use_data_descriptor) {
// Set this flag to denote that a DataDescriptor struct will appear after the data,
// containing the crc and size fields.
dst->gpb_flags |= kGPBDDFlagMask;
// The size and crc fields must be 0.
dst->compressed_size = 0u;
dst->uncompressed_size = 0u;
dst->crc32 = 0u;
} else {
dst->compressed_size = src.compressed_size;
dst->uncompressed_size = src.uncompressed_size;
dst->crc32 = src.crc32;
}
dst->compression_method = src.compression_method;
dst->last_mod_time = src.last_mod_time;
dst->last_mod_date = src.last_mod_date;
dst->file_name_length = src.path.size();
dst->extra_field_length = src.padding_length;
}
int32_t ZipWriter::StartAlignedEntryWithTime(const char* path, size_t flags,
time_t time, uint32_t alignment) {
if (state_ != State::kWritingZip) {
return kInvalidState;
}
if (flags & kAlign32) {
return kInvalidAlign32Flag;
}
if (powerof2(alignment) == 0) {
return kInvalidAlignment;
}
FileEntry file_entry = {};
file_entry.local_file_header_offset = current_offset_;
file_entry.path = path;
if (!IsValidEntryName(reinterpret_cast<const uint8_t*>(file_entry.path.data()),
file_entry.path.size())) {
return kInvalidEntryName;
}
if (flags & ZipWriter::kCompress) {
file_entry.compression_method = kCompressDeflated;
int32_t result = PrepareDeflate();
if (result != kNoError) {
return result;
}
} else {
file_entry.compression_method = kCompressStored;
}
ExtractTimeAndDate(time, &file_entry.last_mod_time, &file_entry.last_mod_date);
off_t offset = current_offset_ + sizeof(LocalFileHeader) + file_entry.path.size();
std::vector<char> zero_padding;
if (alignment != 0 && (offset & (alignment - 1))) {
// Pad the extra field so the data will be aligned.
uint16_t padding = alignment - (offset % alignment);
file_entry.padding_length = padding;
offset += padding;
zero_padding.resize(padding, 0);
}
LocalFileHeader header = {};
// Always start expecting a data descriptor. When the data has finished being written,
// if it is possible to seek back, the GPB flag will reset and the sizes written.
CopyFromFileEntry(file_entry, true /*use_data_descriptor*/, &header);
if (fwrite(&header, sizeof(header), 1, file_) != 1) {
return HandleError(kIoError);
}
if (fwrite(path, sizeof(*path), file_entry.path.size(), file_) != file_entry.path.size()) {
return HandleError(kIoError);
}
if (file_entry.padding_length != 0 &&
fwrite(zero_padding.data(), 1, file_entry.padding_length, file_)
!= file_entry.padding_length) {
return HandleError(kIoError);
}
current_file_entry_ = std::move(file_entry);
current_offset_ = offset;
state_ = State::kWritingEntry;
return kNoError;
}
int32_t ZipWriter::DiscardLastEntry() {
if (state_ != State::kWritingZip || files_.empty()) {
return kInvalidState;
}
FileEntry& last_entry = files_.back();
current_offset_ = last_entry.local_file_header_offset;
if (fseeko(file_, current_offset_, SEEK_SET) != 0) {
return HandleError(kIoError);
}
files_.pop_back();
return kNoError;
}
int32_t ZipWriter::GetLastEntry(FileEntry* out_entry) {
CHECK(out_entry != nullptr);
if (files_.empty()) {
return kInvalidState;
}
*out_entry = files_.back();
return kNoError;
}
int32_t ZipWriter::PrepareDeflate() {
CHECK(state_ == State::kWritingZip);
// Initialize the z_stream for compression.
z_stream_ = std::unique_ptr<z_stream, void(*)(z_stream*)>(new z_stream(), DeleteZStream);
#pragma GCC diagnostic push
#pragma GCC diagnostic ignored "-Wold-style-cast"
int zerr = deflateInit2(z_stream_.get(), Z_BEST_COMPRESSION, Z_DEFLATED, -MAX_WBITS,
DEF_MEM_LEVEL, Z_DEFAULT_STRATEGY);
#pragma GCC diagnostic pop
if (zerr != Z_OK) {
if (zerr == Z_VERSION_ERROR) {
ALOGE("Installed zlib is not compatible with linked version (%s)", ZLIB_VERSION);
return HandleError(kZlibError);
} else {
ALOGE("deflateInit2 failed (zerr=%d)", zerr);
return HandleError(kZlibError);
}
}
z_stream_->next_out = buffer_.data();
z_stream_->avail_out = buffer_.size();
return kNoError;
}
int32_t ZipWriter::WriteBytes(const void* data, size_t len) {
if (state_ != State::kWritingEntry) {
return HandleError(kInvalidState);
}
int32_t result = kNoError;
if (current_file_entry_.compression_method & kCompressDeflated) {
result = CompressBytes(&current_file_entry_, data, len);
} else {
result = StoreBytes(&current_file_entry_, data, len);
}
if (result != kNoError) {
return result;
}
current_file_entry_.crc32 = crc32(current_file_entry_.crc32,
reinterpret_cast<const Bytef*>(data), len);
current_file_entry_.uncompressed_size += len;
return kNoError;
}
int32_t ZipWriter::StoreBytes(FileEntry* file, const void* data, size_t len) {
CHECK(state_ == State::kWritingEntry);
if (fwrite(data, 1, len, file_) != len) {
return HandleError(kIoError);
}
file->compressed_size += len;
current_offset_ += len;
return kNoError;
}
int32_t ZipWriter::CompressBytes(FileEntry* file, const void* data, size_t len) {
CHECK(state_ == State::kWritingEntry);
CHECK(z_stream_);
CHECK(z_stream_->next_out != nullptr);
CHECK(z_stream_->avail_out != 0);
// Prepare the input.
z_stream_->next_in = reinterpret_cast<const uint8_t*>(data);
z_stream_->avail_in = len;
while (z_stream_->avail_in > 0) {
// We have more data to compress.
int zerr = deflate(z_stream_.get(), Z_NO_FLUSH);
if (zerr != Z_OK) {
return HandleError(kZlibError);
}
if (z_stream_->avail_out == 0) {
// The output is full, let's write it to disk.
size_t write_bytes = z_stream_->next_out - buffer_.data();
if (fwrite(buffer_.data(), 1, write_bytes, file_) != write_bytes) {
return HandleError(kIoError);
}
file->compressed_size += write_bytes;
current_offset_ += write_bytes;
// Reset the output buffer for the next input.
z_stream_->next_out = buffer_.data();
z_stream_->avail_out = buffer_.size();
}
}
return kNoError;
}
int32_t ZipWriter::FlushCompressedBytes(FileEntry* file) {
CHECK(state_ == State::kWritingEntry);
CHECK(z_stream_);
CHECK(z_stream_->next_out != nullptr);
CHECK(z_stream_->avail_out != 0);
// Keep deflating while there isn't enough space in the buffer to
// to complete the compress.
int zerr;
while ((zerr = deflate(z_stream_.get(), Z_FINISH)) == Z_OK) {
CHECK(z_stream_->avail_out == 0);
size_t write_bytes = z_stream_->next_out - buffer_.data();
if (fwrite(buffer_.data(), 1, write_bytes, file_) != write_bytes) {
return HandleError(kIoError);
}
file->compressed_size += write_bytes;
current_offset_ += write_bytes;
z_stream_->next_out = buffer_.data();
z_stream_->avail_out = buffer_.size();
}
if (zerr != Z_STREAM_END) {
return HandleError(kZlibError);
}
size_t write_bytes = z_stream_->next_out - buffer_.data();
if (write_bytes != 0) {
if (fwrite(buffer_.data(), 1, write_bytes, file_) != write_bytes) {
return HandleError(kIoError);
}
file->compressed_size += write_bytes;
current_offset_ += write_bytes;
}
z_stream_.reset();
return kNoError;
}
int32_t ZipWriter::FinishEntry() {
if (state_ != State::kWritingEntry) {
return kInvalidState;
}
if (current_file_entry_.compression_method & kCompressDeflated) {
int32_t result = FlushCompressedBytes(&current_file_entry_);
if (result != kNoError) {
return result;
}
}
if ((current_file_entry_.compression_method & kCompressDeflated) || !seekable_) {
// Some versions of ZIP don't allow STORED data to have a trailing DataDescriptor.
// If this file is not seekable, or if the data is compressed, write a DataDescriptor.
const uint32_t sig = DataDescriptor::kOptSignature;
if (fwrite(&sig, sizeof(sig), 1, file_) != 1) {
return HandleError(kIoError);
}
DataDescriptor dd = {};
dd.crc32 = current_file_entry_.crc32;
dd.compressed_size = current_file_entry_.compressed_size;
dd.uncompressed_size = current_file_entry_.uncompressed_size;
if (fwrite(&dd, sizeof(dd), 1, file_) != 1) {
return HandleError(kIoError);
}
current_offset_ += sizeof(DataDescriptor::kOptSignature) + sizeof(dd);
} else {
// Seek back to the header and rewrite to include the size.
if (fseeko(file_, current_file_entry_.local_file_header_offset, SEEK_SET) != 0) {
return HandleError(kIoError);
}
LocalFileHeader header = {};
CopyFromFileEntry(current_file_entry_, false /*use_data_descriptor*/, &header);
if (fwrite(&header, sizeof(header), 1, file_) != 1) {
return HandleError(kIoError);
}
if (fseeko(file_, current_offset_, SEEK_SET) != 0) {
return HandleError(kIoError);
}
}
files_.emplace_back(std::move(current_file_entry_));
state_ = State::kWritingZip;
return kNoError;
}
int32_t ZipWriter::Finish() {
if (state_ != State::kWritingZip) {
return kInvalidState;
}
off_t startOfCdr = current_offset_;
for (FileEntry& file : files_) {
CentralDirectoryRecord cdr = {};
cdr.record_signature = CentralDirectoryRecord::kSignature;
if ((file.compression_method & kCompressDeflated) || !seekable_) {
cdr.gpb_flags |= kGPBDDFlagMask;
}
cdr.compression_method = file.compression_method;
cdr.last_mod_time = file.last_mod_time;
cdr.last_mod_date = file.last_mod_date;
cdr.crc32 = file.crc32;
cdr.compressed_size = file.compressed_size;
cdr.uncompressed_size = file.uncompressed_size;
cdr.file_name_length = file.path.size();
cdr.local_file_header_offset = static_cast<uint32_t>(file.local_file_header_offset);
if (fwrite(&cdr, sizeof(cdr), 1, file_) != 1) {
return HandleError(kIoError);
}
if (fwrite(file.path.data(), 1, file.path.size(), file_) != file.path.size()) {
return HandleError(kIoError);
}
current_offset_ += sizeof(cdr) + file.path.size();
}
EocdRecord er = {};
er.eocd_signature = EocdRecord::kSignature;
er.disk_num = 0;
er.cd_start_disk = 0;
er.num_records_on_disk = files_.size();
er.num_records = files_.size();
er.cd_size = current_offset_ - startOfCdr;
er.cd_start_offset = startOfCdr;
if (fwrite(&er, sizeof(er), 1, file_) != 1) {
return HandleError(kIoError);
}
current_offset_ += sizeof(er);
// Since we can BackUp() and potentially finish writing at an offset less than one we had
// already written at, we must truncate the file.
if (ftruncate(fileno(file_), current_offset_) != 0) {
return HandleError(kIoError);
}
if (fflush(file_) != 0) {
return HandleError(kIoError);
}
state_ = State::kDone;
return kNoError;
}