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/*
* Copyright (c) 2020, Andrés Vieira <anvieiravazquez@gmail.com>
* 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 THE COPYRIGHT HOLDERS AND CONTRIBUTORS "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 THE COPYRIGHT HOLDER 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 <AK/MappedFile.h>
#include <AK/NumberFormat.h>
#include <LibCore/ArgsParser.h>
#include <LibCore/File.h>
#include <string.h>
#include <sys/stat.h>
static const u8 central_directory_file_header_sig[] = "\x50\x4b\x01\x02";
static bool seek_and_read(u8* buffer, const MappedFile& file, off_t seek_to, size_t bytes_to_read)
{
if (!buffer)
return false;
if ((size_t)seek_to >= file.size())
return false;
memcpy(buffer, (const char*)file.data() + seek_to, bytes_to_read);
return true;
}
static bool find_next_central_directory(off_t file_size, const MappedFile& file, off_t current_index, off_t& return_index)
{
off_t start_index = current_index == 0 ? current_index : current_index + 1;
for (off_t index = start_index; index < file_size - 4; index++) {
u8 buffer[4];
if (!seek_and_read(buffer, file, index, 4))
return false;
if (!memcmp(buffer, central_directory_file_header_sig, 4)) {
return_index = index;
return true;
}
}
return false;
}
static bool unpack_file_for_central_directory_index(off_t central_directory_index, const MappedFile& file)
{
enum CentralFileDirectoryHeaderOffsets {
CFDHCompressionMethodOffset = 10,
CFDHLocalFileHeaderIndexOffset = 42,
};
enum LocalFileHeaderOffsets {
LFHCompressionMethodOffset = 8,
LFHCompressedSizeOffset = 18,
LFHFileNameLengthOffset = 26,
LFHExtraFieldLengthOffset = 28,
LFHFileNameBaseOffset = 30,
};
enum CompressionMethod {
None = 0,
Shrunk = 1,
Factor1 = 2,
Factor2 = 3,
Factor3 = 4,
Factor4 = 5,
Implode = 6,
Deflate = 8,
EnhancedDeflate = 9,
PKWareDCLImplode = 10,
BZIP2 = 12,
LZMA = 14,
TERSE = 18,
LZ77 = 19,
};
u8 buffer[4];
if (!seek_and_read(buffer, file, central_directory_index + CFDHLocalFileHeaderIndexOffset, 4))
return false;
off_t local_file_header_index = buffer[3] << 24 | buffer[2] << 16 | buffer[1] << 8 | buffer[0];
if (!seek_and_read(buffer, file, local_file_header_index + LFHCompressionMethodOffset, 2))
return false;
auto compression_method = buffer[1] << 8 | buffer[0];
// FIXME: Remove once any decompression is supported.
ASSERT(compression_method == None);
if (!seek_and_read(buffer, file, local_file_header_index + LFHCompressedSizeOffset, 4))
return false;
off_t compressed_file_size = buffer[3] << 24 | buffer[2] << 16 | buffer[1] << 8 | buffer[0];
if (!seek_and_read(buffer, file, local_file_header_index + LFHFileNameLengthOffset, 2))
return false;
off_t file_name_length = buffer[1] << 8 | buffer[0];
if (!seek_and_read(buffer, file, local_file_header_index + LFHExtraFieldLengthOffset, 2))
return false;
off_t extra_field_length = buffer[1] << 8 | buffer[0];
if (!seek_and_read(buffer, file, local_file_header_index + LFHFileNameBaseOffset, file_name_length))
return false;
char file_name[file_name_length + 1];
memcpy(file_name, buffer, file_name_length);
file_name[file_name_length] = '\0';
if (file_name[file_name_length - 1] == '/') {
if (mkdir(file_name, 0755) < 0) {
perror("mkdir");
return false;
}
} else {
auto new_file = Core::File::construct(String { file_name });
if (!new_file->open(Core::IODevice::WriteOnly)) {
fprintf(stderr, "Can't write file %s: %s\n", file_name, new_file->error_string());
return false;
}
printf(" extracting: %s\n", file_name);
u8 raw_file_contents[compressed_file_size];
if (!seek_and_read(raw_file_contents, file, local_file_header_index + LFHFileNameBaseOffset + file_name_length + extra_field_length, compressed_file_size))
return false;
// FIXME: Try to uncompress data here. We're just ignoring it as no decompression methods are implemented yet.
if (!new_file->write(raw_file_contents, compressed_file_size)) {
fprintf(stderr, "Can't write file contents in %s: %s\n", file_name, new_file->error_string());
return false;
}
if (!new_file->close()) {
fprintf(stderr, "Can't close file %s: %s\n", file_name, new_file->error_string());
return false;
}
}
return true;
}
int main(int argc, char** argv)
{
const char* path;
int map_size_limit = 32 * MB;
Core::ArgsParser args_parser;
args_parser.add_option(map_size_limit, "Maximum chunk size to map", "map-size-limit", 0, "size");
args_parser.add_positional_argument(path, "File to unzip", "path", Core::ArgsParser::Required::Yes);
args_parser.parse(argc, argv);
String zip_file_path { path };
struct stat st;
int rc = stat(zip_file_path.characters(), &st);
if (rc < 0) {
perror("stat");
return 1;
}
// FIXME: Map file chunk-by-chunk once we have mmap() with offset.
// This will require mapping some parts then unmapping them repeatedly,
// but it would be significantly faster and less syscall heavy than seek()/read() at every read.
if (st.st_size >= map_size_limit) {
fprintf(stderr, "unzip warning: Refusing to map file since it is larger than %s, pass '--map-size-limit %d' to get around this\n",
human_readable_size(map_size_limit).characters(),
round_up_to_power_of_two(st.st_size, 16));
return 1;
}
MappedFile mapped_file { zip_file_path };
if (!mapped_file.is_valid())
return 1;
printf("Archive: %s\n", zip_file_path.characters());
off_t index = 0;
while (find_next_central_directory(st.st_size, mapped_file, index, index)) {
bool success = unpack_file_for_central_directory_index(index, mapped_file);
if (!success) {
printf("Could not find local file header for a file.\n");
return 4;
}
}
return 0;
}
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