| /* |
| * Copyright (C) 2011 Apple Inc. All rights reserved. |
| * |
| * Redistribution and use in source and binary forms, with or without |
| * modification, are permitted provided that the following conditions |
| * are met: |
| * 1. Redistributions of source code must retain the above copyright |
| * notice, this list of conditions and the following disclaimer. |
| * 2. Redistributions in binary form must reproduce the above copyright |
| * notice, this list of conditions and the following disclaimer in the |
| * documentation and/or other materials provided with the distribution. |
| * |
| * THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY |
| * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE |
| * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR |
| * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR |
| * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, |
| * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, |
| * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR |
| * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY |
| * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
| * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE |
| * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
| */ |
| |
| #include "config.h" |
| #include "DownloadBundle.h" |
| |
| #include <io.h> |
| #include <sys/stat.h> |
| #include <sys/types.h> |
| #include <wtf/text/CString.h> |
| #include <wtf/text/WTFString.h> |
| |
| namespace WebCore { |
| |
| namespace DownloadBundle { |
| |
| static uint32_t magicNumber() |
| { |
| return 0xDECAF4EA; |
| } |
| |
| const String& fileExtension() |
| { |
| static const NeverDestroyed<String> extension { ".download"_s }; |
| return extension; |
| } |
| |
| bool appendResumeData(const char* resumeBytes, uint32_t resumeLength, const String& bundlePath) |
| { |
| if (!resumeBytes || !resumeLength) { |
| LOG_ERROR("Invalid resume data to write to bundle path"); |
| return false; |
| } |
| if (bundlePath.isEmpty()) { |
| LOG_ERROR("Cannot write resume data to empty download bundle path"); |
| return false; |
| } |
| |
| auto nullifiedPath = bundlePath.wideCharacters(); |
| FILE* bundle = 0; |
| if (_wfopen_s(&bundle, nullifiedPath.data(), TEXT("ab")) || !bundle) { |
| LOG_ERROR("Failed to open file %s to append resume data", bundlePath.ascii().data()); |
| return false; |
| } |
| |
| bool result = false; |
| |
| if (fwrite(resumeBytes, 1, resumeLength, bundle) != resumeLength) { |
| LOG_ERROR("Failed to write resume data to the bundle - errno(%i)", errno); |
| goto exit; |
| } |
| |
| if (fwrite(&resumeLength, 4, 1, bundle) != 1) { |
| LOG_ERROR("Failed to write footer length to the bundle - errno(%i)", errno); |
| goto exit; |
| } |
| |
| const uint32_t magic = magicNumber(); |
| if (fwrite(&magic, 4, 1, bundle) != 1) { |
| LOG_ERROR("Failed to write footer magic number to the bundle - errno(%i)", errno); |
| goto exit; |
| } |
| |
| result = true; |
| exit: |
| fclose(bundle); |
| return result; |
| } |
| |
| bool extractResumeData(const String& bundlePath, Vector<char>& resumeData) |
| { |
| if (bundlePath.isEmpty()) { |
| LOG_ERROR("Cannot create resume data from empty download bundle path"); |
| return false; |
| } |
| |
| // Open a handle to the bundle file |
| auto nullifiedPath = bundlePath.wideCharacters(); |
| FILE* bundle = 0; |
| if (_wfopen_s(&bundle, nullifiedPath.data(), TEXT("r+b")) || !bundle) { |
| LOG_ERROR("Failed to open file %s to get resume data", bundlePath.ascii().data()); |
| return false; |
| } |
| |
| bool result = false; |
| |
| // Stat the file to get its size |
| struct _stat64 fileStat; |
| if (_fstat64(_fileno(bundle), &fileStat)) |
| goto exit; |
| |
| // Check for the bundle magic number at the end of the file |
| fpos_t footerMagicNumberPosition = fileStat.st_size - 4; |
| ASSERT(footerMagicNumberPosition >= 0); |
| if (footerMagicNumberPosition < 0) |
| goto exit; |
| if (fsetpos(bundle, &footerMagicNumberPosition)) |
| goto exit; |
| |
| uint32_t footerMagicNumber = 0; |
| if (fread(&footerMagicNumber, 4, 1, bundle) != 1) { |
| LOG_ERROR("Failed to read footer magic number from the bundle - errno(%i)", errno); |
| goto exit; |
| } |
| |
| if (footerMagicNumber != magicNumber()) { |
| LOG_ERROR("Footer's magic number does not match 0x%X - errno(%i)", magicNumber(), errno); |
| goto exit; |
| } |
| |
| // Now we're *reasonably* sure this is a .download bundle we actually wrote. |
| // Get the length of the resume data |
| fpos_t footerLengthPosition = fileStat.st_size - 8; |
| ASSERT(footerLengthPosition >= 0); |
| if (footerLengthPosition < 0) |
| goto exit; |
| |
| if (fsetpos(bundle, &footerLengthPosition)) |
| goto exit; |
| |
| uint32_t footerLength = 0; |
| if (fread(&footerLength, 4, 1, bundle) != 1) { |
| LOG_ERROR("Failed to read ResumeData length from the bundle - errno(%i)", errno); |
| goto exit; |
| } |
| |
| // Make sure theres enough bytes to read in for the resume data, and perform the read |
| fpos_t footerStartPosition = fileStat.st_size - 8 - footerLength; |
| ASSERT(footerStartPosition >= 0); |
| if (footerStartPosition < 0) |
| goto exit; |
| if (fsetpos(bundle, &footerStartPosition)) |
| goto exit; |
| |
| resumeData.resize(footerLength); |
| if (fread(resumeData.data(), 1, footerLength, bundle) != footerLength) { |
| LOG_ERROR("Failed to read ResumeData from the bundle - errno(%i)", errno); |
| goto exit; |
| } |
| |
| // CFURLDownload will seek to the appropriate place in the file (before our footer) and start overwriting from there |
| // However, say we were within a few hundred bytes of the end of a download when it was paused - |
| // The additional footer extended the length of the file beyond its final length, and there will be junk data leftover |
| // at the end. Therefore, now that we've retrieved the footer data, we need to truncate it. |
| if (errno_t resizeError = _chsize_s(_fileno(bundle), footerStartPosition)) { |
| LOG_ERROR("Failed to truncate the resume footer off the end of the file - errno(%i)", resizeError); |
| goto exit; |
| } |
| |
| result = true; |
| exit: |
| fclose(bundle); |
| return result; |
| } |
| |
| } // namespace DownloadBundle |
| |
| } // namespace WebCore |