LibArchive: Implement a basic parser for tar extended headers

This commit is contained in:
Tim Schumacher 2022-03-04 19:32:51 +01:00 committed by Andreas Kling
parent ff19c1cffe
commit f6e86915f5
Notes: sideshowbarker 2024-07-17 17:54:53 +09:00

View file

@ -40,6 +40,9 @@ public:
const TarFileHeader& header() const { return m_header; }
TarFileStream file_contents();
template<VoidFunction<StringView, StringView> F>
ErrorOr<void> for_each_extended_header(F func);
private:
TarFileHeader m_header;
InputStream& m_stream;
@ -64,4 +67,51 @@ private:
friend class TarFileStream;
};
template<VoidFunction<StringView, StringView> F>
inline ErrorOr<void> TarInputStream::for_each_extended_header(F func)
{
VERIFY(header().content_is_like_extended_header());
Archive::TarFileStream file_stream = file_contents();
ByteBuffer file_contents_buffer = TRY(ByteBuffer::create_zeroed(header().size()));
VERIFY(file_stream.read(file_contents_buffer) == header().size());
StringView file_contents { file_contents_buffer };
while (!file_contents.is_empty()) {
// Split off the length (until the first space).
Optional<size_t> length_end_index = file_contents.find(' ');
if (!length_end_index.has_value())
return Error::from_string_literal("Malformed extended header: No length found.");
Optional<unsigned int> length = file_contents.substring_view(0, length_end_index.value()).to_uint();
if (!length.has_value())
return Error::from_string_literal("Malformed extended header: Could not parse length.");
unsigned int remaining_length = length.value();
remaining_length -= length_end_index.value() + 1;
file_contents = file_contents.substring_view(length_end_index.value() + 1);
// Extract the header.
StringView header = file_contents.substring_view(0, remaining_length - 1);
file_contents = file_contents.substring_view(remaining_length - 1);
// Ensure that the header ends at the expected location.
if (file_contents.length() < 1 || !file_contents.starts_with('\n'))
return Error::from_string_literal("Malformed extended header: Header does not end at expected location.");
file_contents = file_contents.substring_view(1);
// Find the delimiting '='.
Optional<size_t> header_delimiter_index = header.find('=');
if (!header_delimiter_index.has_value())
return Error::from_string_literal("Malformed extended header: Header does not have a delimiter.");
StringView key = header.substring_view(0, header_delimiter_index.value());
StringView value = header.substring_view(header_delimiter_index.value() + 1);
func(key, value);
}
return {};
}
}