OpenHarmony-v6.0-Release/s

/*
 * Copyright (c) 2022 Huawei Device Co., Ltd.
 * 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 "zip_reader.h"

#include <stdio.h>
#include <time.h>
#include <unistd.h>
#include <utility>

#include "app_log_wrapper.h"
#include "checked_cast.h"
#include "contrib/minizip/unzip.h"
#include "string_ex.h"
#include "zip_internal.h"
#include "zip_utils.h"

using namespace OHOS::AppExecFwk;

namespace OHOS {
namespace AppExecFwk {
namespace LIBZIP {

// The implementation assumes that file names in zip files
// are encoded in UTF-8. This is true for zip files created by Zip()
// function in zip.h, but not true for user-supplied random zip files.
ZipReader::EntryInfo::EntryInfo(const std::string &fileNameInZip, const unz_file_info &rawFileInfo)
    : filePath_(FilePath::FromUTF8Unsafe(fileNameInZip)), isDirectory_(false), isUnsafe_(false), isEncrypted_(false)
{
    originalSize_ = rawFileInfo.uncompressed_size;

    // Directory entries in zip files end with "/".
    isDirectory_ = EndsWith(fileNameInZip, "/");

    // Check the file name here for directory traversal issues.
    isUnsafe_ = filePath_.ReferencesParent();

    // Whether the file is encrypted is bit 0 of the flag.
    isEncrypted_ = rawFileInfo.flag & 1;

    // Construct the last modified time. The timezone info is not present in
    // zip files, so we construct the time as local time.
    if (GetCurrentSystemTime() != nullptr) {
        lastModified_ = *GetCurrentSystemTime();
    }
}

ZipReader::ZipReader()
{
    Reset();
}

ZipReader::~ZipReader()
{
    Close();
}

bool ZipReader::Open(FilePath &zipFilePath)
{
    if (zipFile_ != nullptr) {
        return false;
    }

    // Use of "Unsafe" function does not look good, but there is no way to do
    // this safely on Linux. See file_util.h for details.
    std::string zipfile = zipFilePath.Value();
    zipFile_ = OpenForUnzipping(zipfile);
    if (zipFile_ == nullptr) {
        return false;
    }

    return OpenInternal();
}

bool ZipReader::OpenFromPlatformFile(PlatformFile zipFd)
{
    if (zipFile_ != nullptr) {
        return false;
    }
    zipFile_ = OpenFdForUnzipping(zipFd);
    if (!zipFile_) {
        return false;
    }

    return OpenInternal();
}

bool ZipReader::OpenFromString(const std::string &data)
{
    zipFile_ = PrepareMemoryForUnzipping(data);
    if (!zipFile_) {
        return false;
    }

    return OpenInternal();
}

void ZipReader::Close()
{
    if (zipFile_) {
        unzClose(zipFile_);
    }
    Reset();
}

bool ZipReader::HasMore()
{
    return !reachedEnd_;
}

bool ZipReader::AdvanceToNextEntry()
{
    if (zipFile_ == nullptr) {
        return false;
    }
    // Should not go further if we already reached the end.
    if (reachedEnd_) {
        return false;
    }
    unz_file_pos position = {};
    if (unzGetFilePos(zipFile_, &position) != UNZ_OK) {
        return false;
    }

    const int currentEntryIndex = position.num_of_file;
    // If we are currently at the last entry, then the next position is the
    // end of the zip file, so mark that we reached the end.
    if (currentEntryIndex + 1 == numEntries_) {
        reachedEnd_ = true;
    } else {
        if (unzGoToNextFile(zipFile_) != UNZ_OK) {
            return false;
        }
    }
    currentEntryInfo_.reset();
    return true;
}

bool ZipReader::GetCurrentEntryPos(unz_file_pos &filePos)
{
    if (unzGetFilePos(zipFile_, &filePos) != UNZ_OK) {
        return false;
    }
    return true;
}

bool ZipReader::OpenCurrentEntryInZip()
{
    if (zipFile_ == nullptr) {
        return false;
    }

    unz_file_info raw_file_info = {};
    char raw_file_name_in_zip[kZipMaxPath] = {};
    const int result = unzGetCurrentFileInfo(zipFile_,
        &raw_file_info,
        raw_file_name_in_zip,
        sizeof(raw_file_name_in_zip) - 1,
        NULL,  // extraField.
        0,     // extraFieldBufferSize.
        NULL,  // szComment.
        0);    // commentBufferSize.
    if (result != UNZ_OK) {
        APP_LOGE("unzGetCurrentFileInfo %{public}d", result);
        return false;
    }
    if (raw_file_name_in_zip[0] == '\0') {
        return false;
    }
    EntryInfo *entryInfo = new (std::nothrow) EntryInfo(std::string(raw_file_name_in_zip), raw_file_info);
    if (entryInfo == nullptr) {
        return false;
    }
    currentEntryInfo_.reset(entryInfo);
    return true;
}

bool ZipReader::ExtractCurrentEntry(WriterDelegate *delegate, uint64_t numBytesToExtract) const
{
    return ExtractEntry(delegate, zipFile_, numBytesToExtract);
}

bool ZipReader::ExtractEntry(WriterDelegate *delegate, const unzFile &zipFile, uint64_t numBytesToExtract) const
{
    if ((zipFile == nullptr) || (delegate == nullptr)) {
        return false;
    }
    const int openResult = unzOpenCurrentFile(zipFile);
    if (openResult != UNZ_OK) {
        APP_LOGW("unzOpen err %{public}d", openResult);
        return false;
    }
    auto buf = std::make_unique<char[]>(kZipBufSize);
    uint64_t remainingCapacity = numBytesToExtract;
    bool entirefileextracted = false;

    while (remainingCapacity > 0) {
        const int numBytesRead = unzReadCurrentFile(zipFile, buf.get(), kZipBufSize);
        if (numBytesRead == 0) {
            entirefileextracted = true;
            APP_LOGD("extract entry");
            break;
        } else if (numBytesRead < 0) {
            // If numBytesRead < 0, then it's a specific UNZ_* error code.
            APP_LOGE("unzReadCurrentFile < 0 %{public}d", numBytesRead);
            break;
        } else {
            uint64_t numBytesToWrite = std::min<uint64_t>(remainingCapacity, checked_cast<uint64_t>(numBytesRead));
            if (!delegate->WriteBytes(buf.get(), numBytesToWrite)) {
                APP_LOGE("WriteBytes %{public}lu", (unsigned long) numBytesToWrite);
                break;
            }
            if (remainingCapacity == checked_cast<uint64_t>(numBytesRead)) {
                // Ensures function returns true if the entire file has been read.
                entirefileextracted = (unzReadCurrentFile(zipFile, buf.get(), 1) == 0);
                APP_LOGI("extract entry %{public}d", entirefileextracted);
            }
            if (remainingCapacity >= numBytesToWrite) {
                remainingCapacity -= numBytesToWrite;
            }
        }
    }

    unzCloseCurrentFile(zipFile);
    // closeFile
    delegate->SetTimeModified(GetCurrentSystemTime());

    return entirefileextracted;
}

bool ZipReader::OpenInternal()
{
    if (zipFile_ == nullptr) {
        return false;
    }

    unz_global_info zipInfo = {};  // Zero-clear.
    if (unzGetGlobalInfo(zipFile_, &zipInfo) != UNZ_OK) {
        return false;
    }
    numEntries_ = zipInfo.number_entry;
    if (numEntries_ < 0) {
        return false;
    }

    // We are already at the end if the zip file is empty.
    reachedEnd_ = (numEntries_ == 0);
    return true;
}

void ZipReader::Reset()
{
    zipFile_ = nullptr;
    numEntries_ = 0;
    reachedEnd_ = false;
    currentEntryInfo_.reset();
}

// ZipParallelReader
ZipParallelReader::~ZipParallelReader()
{
    Close();
}

bool ZipParallelReader::Open(FilePath &zipFilePath)
{
    if (!zipFiles_.empty()) {
        return false;
    }
    if (!ZipReader::Open(zipFilePath)) {
        return false;
    }

    unzFile zipFile;
    std::string zipFilePathValue = zipFilePath.Value();
    for (int32_t i = 0; i < concurrency_; i++) {
        zipFile = OpenForUnzipping(zipFilePathValue);
        if (!zipFile) {
            return false;
        }
        zipFiles_.push_back(zipFile);
    }
    return true;
}

bool ZipParallelReader::GotoEntry(unzFile &zipFile, unz_file_pos filePos)
{
    if (zipFile == nullptr) {
        return false;
    }
    if (static_cast<int>(filePos.num_of_file) >= ZipReader::num_entries()) {
        return false;
    }

    if (unzGoToFilePos(zipFile, &filePos) != UNZ_OK) {
        return false;
    }
    return true;
}

unzFile ZipParallelReader::GetZipHandler(int &resourceId)
{
    resourceId %= concurrency_;
    while (!mtxes_[resourceId].try_lock()) {
        resourceId = (resourceId + 1) % concurrency_;
    }
    return zipFiles_[resourceId];
}

void ZipParallelReader::ReleaseZipHandler(const int &resourceId)
{
    mtxes_[resourceId].unlock();
}

void ZipParallelReader::Close()
{
    ZipReader::Close();
    for (unzFile zipFile : zipFiles_) {
        unzClose(zipFile);
    }
}

// FilePathWriterDelegate
FilePathWriterDelegate::FilePathWriterDelegate(const FilePath &outputFilePath) : outputFilePath_(outputFilePath)
{}

FilePathWriterDelegate::~FilePathWriterDelegate()
{}

bool FilePathWriterDelegate::PrepareOutput()
{
    if (!FilePathCheckValid(outputFilePath_.Value())) {
        APP_LOGE("outputFilePath_ invalid");
        return false;
    }
    // We can't rely on parent directory entries being specified in the
    // zip, so we make sure they are created.
    if (!FilePath::CreateDirectory(outputFilePath_.DirName())) {
        return false;
    }

    file_ = fopen(outputFilePath_.Value().c_str(), "wb");
    if (file_ == nullptr) {
        APP_LOGE("fopen %{private}s err: %{public}d %{public}s",
            outputFilePath_.Value().c_str(), errno, strerror(errno));
        return false;
    }
    return FilePath::PathIsValid(outputFilePath_);
}

bool FilePathWriterDelegate::WriteBytes(const char *data, int numBytes)
{
    if ((file_ == nullptr) || (numBytes <= 0) || (data == nullptr)) {
        return false;
    }
    int writebytes = fwrite(data, 1, numBytes, file_);
    bool ret = (numBytes == writebytes);
    if (!ret) {
        APP_LOGE("fwrite %{public}d %{public}d", numBytes, writebytes);
    }
    return ret;
}

void FilePathWriterDelegate::SetTimeModified(const struct tm *time)
{
    if (file_ != nullptr) {
        fclose(file_);
        file_ = nullptr;
    }
}

}  // namespace LIBZIP
}  // namespace AppExecFwk
}  // namespace OHOS