Package-level declarations

The BEP-10 extension-protocol handshake: the bencoded dict exchanged as extended message id 0 right after the BitTorrent handshake (when the extension reserved bit is set). Port of libtorrent's bt_peer_connection::write_extensions / parse_extensions.

Reassembles the metadata (info) blob from incoming UtMetadata data pieces and verifies it against the expected info-hash. This is the codec-side counterpart of ut_metadata_plugin::received_metadata / metadata_request in ut_metadata.cpp.

BEP-9 "Extension for Peers to Send Metadata Files" (ut_metadata). This is the pure message codec, ported from libtorrent's ut_metadata.cpp (src/ut_metadata.cpp, ut_metadata_peer_plugin::write_metadata_packet and on_extended).

BEP-11 "Peer Exchange (PEX)" (ut_pex). This is the pure message codec, ported from libtorrent's ut_pex.cpp (src/ut_pex.cpp, ut_pex_plugin::tick builds the message and ut_pex_peer_plugin::on_extended parses it).