libp2p

• Remove the deprecated libp2p-secio dependency. To continue to use SECIO, add an explicit dependency on libp2p-secio. However, transitioning to libp2p-noise is strongly recommended.

• Update libp2p-yamux to 0.22.0. This version starts a multi-release upgrade process. See the libp2p-yamux CHANGELOG for details.

• Bump libp2p-noise to 0.24. See the libp2p-noise changelog for details about the LegacyConfig.

• The ProtocolsHandler in libp2p-swarm has a new associated type InboundOpenInfo (PR 1714).

• Update libp2p-core, libp2p-gossipsub, libp2p-kad, libp2p-mdns, libp2p-ping, libp2p-request-response, libp2p-swarm and dependent crates.

NOTE: For a smooth upgrade path from 0.21 to > 0.22 on an existing deployment, this version must not be skipped or the provided legacy configuration for libp2p-noise used!

• Bump libp2p-noise dependency to 0.22. See the libp2p-noise changelog for details about the LegacyConfig.

• Refactored bandwidth logging (PR 1670).

NOTE: For a smooth upgrade path from 0.21 to > 0.22 on an existing deployment using libp2p-noise, this version must not be skipped!

• Bump libp2p-noise dependency to 0.21.

• Bump libp2p-websockets lower bound.

• Conditional compilation fixes for the wasm32-wasi target (PR 1633).

• New libp2p-request-response crate (PR 1596).

• Updated libp2p dependencies.

• Temporarily pin all async-std dependencies to < 1.6. PR 1589

• libp2p-core-derive: Fully qualified std::result::Result in macro PR 1587

• libp2p-core, libp2p-swarm: Added support for multiple dialing attempts per peer, with a configurable limit. PR 1506

• libp2p-core: PeerIds that use the identity hashing will now be properly displayed using the string representation of an identity multihash, rather than the canonical SHA 256 representation. PR 1576

• libp2p-core: Updated to multihash 0.11.0. PR 1566

• libp2p-core: Make the number of events buffered to/from tasks configurable. PR 1574

• libp2p-dns, parity-multiaddr: Added support for the /dns multiaddr protocol. Additionally, the multiaddr::from_url function will now use /dns instead of /dns4. PR 1575

• libp2p-noise: Added the X25519Spec protocol suite which uses libp2p-noise-spec compliant signatures on static keys as well as the /noise protocol upgrade, hence providing a libp2p-noise-spec compliant XX handshake. IK and IX are still supported with X25519Spec though not guaranteed to be interoperable with other libp2p implementations as these handshake patterns are not currently included in the libp2p-noise-spec. The X25519Spec implementation will eventually replace the current X25519 implementation, with the former being removed. To upgrade without interruptions, you may temporarily include NoiseConfigs for both implementations as alternatives in your transport upgrade pipeline.

• libp2p-kad: Consider fixed (K_VALUE) amount of peers at closest query initialization. Unless KademliaConfig::set_replication_factor is used change has no effect. PR 1536

• libp2p-kad: Provide more insight into, and control of, the execution of queries. All query results are now wrapped in KademliaEvent::QueryResult. As a side-effect of these changes and for as long as the record storage API is not asynchronous, local storage errors on put_record are reported synchronously in a Result, instead of being reported asynchronously by an event. PR 1567

• libp2p-tcp, libp2p: Made the libp2p-tcp/async-std feature flag disabled by default, and split the libp2p/tcp feature in two: tcp-async-std and tcp-tokio. tcp-async-std is still enabled by default. PR 1471

• libp2p-tcp: On listeners started with an IPv6 multi-address the socket option IPV6_V6ONLY is set to true. Instead of relying on IPv4-mapped IPv6 address support, two listeners can be started if IPv4 and IPv6 should both be supported. IPv4 listener addresses are not affected by this change. PR 1555

• libp2p-swarm: Make sure inject_dial_failure is called in all situations. PR 1549

• libp2p-core: Treat connection limit errors as pending connection errors. PR 1546

• libp2p-core-derive: Disambiguate calls to NetworkBehaviour::inject_event. PR 1543

• libp2p-floodsub: Allow sent messages seen as subscribed. PR 1520

• libp2p-kad: Return peers independent of record existence. PR 1544

• libp2p-wasm-ext: Fix "parsed is null" errors being thrown. PR 1535

• libp2p-core: Finished "identity hashing" for peer IDs migration. PR 1460

• libp2p-core: Remove poll_broadcast. PR 1527

• libp2p-core, libp2p-swarm: Report addresses of closed listeners. PR 1485

• libp2p-core: Support for multiple connections per peer and configurable connection limits. See PR #1440, PR #1519 and issue #912 for details.

• libp2p-swarm: Pass the cause of closing a listener to inject_listener_closed. PR 1517

• libp2p-swarm: Support for multiple connections per peer and configurable connection limits. See PR #1440, PR #1519 and issue #912 for details.

• libp2p-swarm: The SwarmEvent now returns more events. PR 1515

• libp2p-swarm: New protocols_handler::multi module. PR 1497

• libp2p-swarm: Allow configuration of outbound substreams. PR 1521

• libp2p-kad: Providers returned from a lookup are now deduplicated. PR 1528

• libp2p-kad: Allow customising the maximum packet size. PR 1502

• libp2p-kad: Allow customising the (libp2p) connection keep-alive timeout. PR 1477

• libp2p-kad: Avoid storing records that are expired upon receipt (optimisation). PR 1496

• libp2p-kad: Fixed potential panic on computing record expiry. PR 1492

• libp2p-mplex: Guard against use of underlying Sink upon error or connection close. PR 1529

• multistream-select: Upgrade to stable futures. PR 1484

• multihash: Removed the crate in favour of the upstream crate. PR 1472

• Fixed yamux connections not properly closing and being stuck in the CLOSE_WAIT state.
• Added a websocket_transport() function in libp2p-wasm-ext, behind a Cargo feature.
• Fixed ambiguity in IntoProtocolsHandler::select vs ProtocolsHandler::select in the NetworkBehaviour custom derive.

• Fixed wrong representation of PeerIds being used in Kademlia::get_closest_peers.
• Implemented FusedStream for Swarm.

• Removed the Substream associated type from the ProtocolsHandler trait. The type of the substream is now always libp2p::swarm::NegotiatedSubstream.
• As a consequence of the previous change, most of the implementations of the NetworkBehaviour trait provided by libp2p (Ping, Identify, Kademlia, Floodsub, Gossipsub) have lost a generic parameter.
• Removed the first generic parameter (the transport) from Swarm and ExpandedSwarm. The transport is now abstracted away in the internals of the swarm.
• The Send and 'static bounds are now enforced directly on the ProtocolsHandler trait and its associated InboundUpgrade and OutboundUpgrade implementations.
• Modified PeerIds to compare equal across the identity and SHA256 hashes. As a consequence, the Borrow implementation of PeerId now always returns the bytes representation of a multihash with a SHA256 hash.
• Modified libp2p-floodsub to no longer hash the topic. The new behaviour is now compatible with go-libp2p and js-libp2p, but is a breaking change with regards to rust-libp2p.
• Added libp2p-pnet. It makes it possible to protect networks with a pre-shared key (PSK).
• Modified the poll_method parameter of the NetworkBehaviour custom derive. The expected method now takes an additional parameter of type impl PollParameters to be consistent with the NetworkBehaviour::poll method.
• libp2p-noise now compiles for WASM targets.
• Changed libp2p-noise to grow its memory buffers dynamically. This should reduce the overall memory usage of connections that use the noise encryption.
• Fixed libp2p-gossipsub to no longer close the connection if the inbound substream is closed by the remote.
• All crates prefixed with libp2p- now use the same version number.
• Added a new variant ListenerEvent::Error for listeners to report non-fatal errors. libp2p-tcp uses this variant to report errors that happen on remote sockets before they have been accepted and errors when trying to determine the local machine's IP address.

• Added libp2p-gossipsub.
• Added SwarmBuilder::executor to allow configuring which tasks executor to use.
• Added TokioTcpConfig in libp2p-tcp and TokioUdsConfig in libp2p-uds behind tokio features. These structs use tokio and require a tokio runtime executor to be configured via SwarmBuilder::executor.
• Changed the OutboundUpgrade and InboundUpgrade traits to no longer be passed a Negotiated<C> but just a C. The Negotiated is now in the trait bounds requirements of ProtocolsHandler.
• Fixed libp2p-wasm-ext returning Err(WouldBlock) rather than Pending.
• Fixed libp2p-dns not segregating DNS4 and DNS6.
• Removed some unnecessary Unpin requirements on futures.
• Changed Mdns::new to no longer be async.
• Fixed libp2p-kad keeping connections alive when it shouldn't.
• Fixed InboundUpgrade not always properly implemented on NoiseConfig.

• Upgraded the crate to stable futures.
• Use varints instead of fixed sized (4 byte) integers to delimit plaintext 2.0 messages to align implementation with the specification.
• Refactored the core::upgrade module to provide async functions.
• Changed the Stream trait implementation of Swarm to no longer return a Result.
• Added the Swarm::next and Swarm::next_event functions and the SwarmEvent enum.
• Changed ProtocolsHandler::poll to no longer return an error. Instead, ProtocolsHandlerEvent has a new Close variant which corresponds to what an error represented before.
• Changed all the traits that have a poll function (i.e. NetworkBehaviour, ProtocolsHandler, NodeHandler) to have an additional &mut Context parameter, to reflect the changes in the Future trait.
• Revamped the API of libp2p_websockets::framed.
• Added protocol string to Error::UnknownProtocolString.

• Fixed the libp2p-noise handshake not flushing the underlying stream before waiting for a response.
• Fixed semver issue with the protobuf crate.

• Maintenance release to bump dependencies and deal with an accidental breaking change in multihash 0.1.4.

• Reworked the transport upgrade API. See https://github.com/libp2p/rust-libp2p/pull/1240 for more information.
• Added a parameter allowing to choose the protocol negotiation protocol when upgrading a connection or a substream. See https://github.com/libp2p/rust-libp2p/pull/1245 for more information.
• Added an alternative multistream-select protocol called V1Lazy.
• Added PlainText2Config that implements the /plaintext/2.0.0 protocol.
• Refactored libp2p-identify. Some items have been renamed.
• Now accepting PeerIds using the identity hashing algorithm as valid.
• Removed libp2p-observed and libp2p-ratelimit.
• Fixed mDNS long peer IDs not being transmitted properly.
• Added some Debug trait implementations.
• Fixed potential arithmetic overflows in libp2p-kad and multistream-select.

• In some situations, multistream-select will now assume that protocol negotiation immediately succeeds. If it turns out that it failed, an error is generated when reading or writing from/to the stream.
• Replaced listen_addr with local_addr in events related to incoming connections. The address no longer has to match a previously-reported address.
• Listeners now have an identifier and can be stopped.
• Added NetworkBehaviour::inject_listener_error and NetworkBehaviour::inject_listener_closed. For diagnostic purposes, listeners can now report errors on incoming connections, such as when calling accept(2) fails.
• Fixed tasks sometimes not being notified when a network event happens in libp2p-mplex.
• Fixed a memory leak in libp2p-kad.
• Added Toggle::is_enabled().
• Removed IdentifyTransport.

• libp2p-kad: Completed the core functionality of the record storage API, thereby extending the RecordStore for provider records. All records expire by default and are subject to regular republication and caching as per the Kademlia spec(s). Expiration and publication intervals are configurable through the KademliaConfig.
• libp2p-kad: The routing table now never stores peers without a known (listen) address. In particular, on receiving a new inbound connection, the Kademlia behaviour now emits KademliaEvent::UnroutablePeer to indicate that in order for the peer to be added to the routing table and hence considered a reachable node in the DHT, a listen address of the peer must be discovered and reported via Kademlia::add_address. This is usually achieved through the use of the Identify protocol on the same connection(s).
• libp2p-kad: Documentation updates.
• Extracted the swarm and protocols_handler-related contents from libp2p-core to a new libp2p-swarm crate.
• Renamed RawSwarm to Network.
• Added Floodsub::publish_any.
• Replaced unbounded channels with bounded ones at the boundary between the Network (formerly RawSwarm) and NodeHandler. The node handlers will now wait if the main task is busy, instead of continuing to push events to the channel.
• Fixed the address_translation function ignoring /dns addresses.

• PollParameters is now a trait instead of a struct.
• The Swarm can now be customized with connection information.
• Fixed write-only substreams now delivering data properly.
• Fixed the TCP listener accidentally shutting down if an incoming socket was closed too quickly.
• Improved the heuristics for determining external multiaddresses based on reports.
• Various fixes to Kademlia iterative queries and the WebSockets transport.

• EitherOutput now implements Stream and Sink if their variants also implement these traits.
• libp2p::websocket::error::Error now implements Sync.

• Major fixes and performance improvements to libp2p-kad.
• Initial prototype for record storage in libp2p-kad.
• Rewrote the implementation of WebSockets. It now properly supports WebSockets Secure (WSS).
• Removed BrowserWsConfig. Please use libp2p::wasm_ext::ExtTransport instead.
• Added a Path parameter to multiaddr::Protocol::WS and WSS. The string representation when a path is present is respectively x-parity-ws/<path> and x-parity-wss/<path> where <path> is percent-encoded.
• Fixed an issue with libp2p-tcp where the wrong listened address was returned, if the actual address was loopback.
• Added core::upgrade::OptionalUpgrade.
• Added some utility functions in core::identity::secp256k1.
• It is now possible to inject an artificial connection in the RawSwarm.

• Fixed a vulnerability in ED25519 signatures verification in libp2p-core.

• Crate now successfully runs from within the browser when compiled to WASM.
• Modified the constructors of NoiseConfig to accept any type of public key. The Noise handshake has consequently been modified.
• Changed the StreamMuxer trait to have an Error associated type.
• The Swarm now ranks externally-visible multiaddresses by how often they have been reported, ensuring that weird or malicious reports don't affect connectivity too much.
• Added IntoProtocolsHandler::inbound_protocol. Must return the same value as what ProtocolsHandler::listen_protocol would return.
• IntoProtocolsHandler::into_handler now takes a second parameter with the &ConnectedPoint to the node we are connected to.
• Replaced the secp256k1 crate with libsecp256k1.
• Fixed Kademlia::add_providing taking a PeerId instead of a Multihash.
• Fixed various bugs in the implementation of Kademlia.
• Added OneSubstreamMuxer.
• Added the libp2p-wasm-ext crate.
• Added multiaddr::from_url.
• Added OptionalTransport.

• Fixed the inactive connections shutdown mechanism not working.
• Transport::listen_on must now return a Stream that produces ListenEvents. This makes it possible to notify about listened addresses at a later point in time.
• Transport::listen_on no longer returns an address we're listening on. This is done through ListenEvents. All other listen_on methods have been updated accordingly.
• Added NetworkBehaviour::inject_new_listen_addr, NetworkBehaviour::inject_expired_listen_addr and NetworkBehaviour::inject_new_external_addr.
• ProtocolsHandler::listen_protocol and ProtocolsHandlerEvent::OutboundSubstreamRequest must now return a SubstreamProtocol struct containing a timeout for the upgrade.
• Ping::new now requires a PingConfig, which can be created with PingConfig::new.
• Removed Transport::nat_traversal in favour of a stand-alone address_translation function in libp2p-core.
• Reworked the API of Multiaddr.
• Removed the ToMultiaddr trait in favour of TryFrom.
• Added Swarm::ban_peer_id and Swarm::unban_peer_id.
• The TPeerId generic parameter of RawSwarm is now TConnInfo and must now implement a ConnectionInfo trait.
• Reworked the PingEvent.
• Renamed KeepAlive::Forever to Yes and KeepAlive::Now to No.

• Replaced NetworkBehaviour::inject_dial_failure with inject_dial_failure and inject_addr_reach_failure. The former is called when we have finished trying to dial a node without success, while the latter is called when we have failed to reach a specific address.
• Fixed Kademlia storing a different hash than the reference implementation.
• Lots of bugfixes in Kademlia.
• Modified the InboundUpgrade and OutboundUpgrade trait to take a Negotiated<TSocket> instead of TSocket.
• PollParameters::external_addresses now returns Multiaddres as reference instead of by value.
• Added Swarm::external_addresses.
• Added a core::swarm::toggle::Toggle that allows having a disabled NetworkBehaviour.

• Moved the SecioKeypair struct in core/identity and renamed it to Keypair.
• mplex now supports half-closed substreams.
• Renamed StreamMuxer::shutdown() to close().
• Closing a muxer with the close() method (formerly shutdown) now "destroys" all the existing substreams. After close() as been called, they all return either EOF or an error.
• The shutdown_substream() method now closes only the writing side of the substream, and you can continue reading from it until EOF or until you delete it. This was actually already more or less the case before, but it wasn't properly reflected in the API or the documentation.
• poll_inbound() and poll_outbound() no longer return an Option, as None was the same as returning an error.
• Removed the NodeClosed events and renamed NodeError to NodeClosed. From the API's point of view, a connection now always closes with an error.
• Added the NodeHandlerWrapperError enum that describes an error generated by the protocols handlers grouped together. It is either UselessTimeout or Handler. This allows properly reporting closing a connection because it is useless.
• Removed NodeHandler::inject_inbound_closed, NodeHandler::inject_outbound_closed, NodeHandler::shutdown, and ProtocolsHandler::shutdown. The handler is now dropped when a shutdown process starts. This should greatly simplify writing a handler.
• StreamMuxer::close now implies flush_all.
• Removed the Shutdown enum from stream_muxer.
• Removed ProtocolsHandler::fuse().
• Reworked some API of core/nodes/node.rs and core/nodes/handled_node.rs.
• The core now works even outside of a tokio context.

• Fixed periodic pinging not working.

• Fixed wrong version of libp2p-noise.

• The multiaddr! macro has been moved to the multiaddr crate and is now reexported under the name build_multiaddr!.
• Modified the functions in upgrade::transfer to be more convenient to use.
• Now properly sending external addresses in the identify protocol.
• Fixed duplicate addresses being reported in identify and Kademlia.
• Fixed infinite looping in the functions in upgrade::transfer.
• Fixed infinite loop on graceful node shutdown with the ProtocolsHandlerSelect.
• Fixed various issues with nodes dialing each other simultaneously.
• Added the StreamMuxer::is_remote_acknowledged() method.
• Added a BandwidthLogging transport wrapper that logs the bandwidth consumption.
• The addresses to try dialing when dialing a node is now refreshed by the Swarm when necessary.
• Lots of modifications to the semi-private structs in core/nodes.
• Added IdentifyEvent::SendBack, when we send back our information.
• Rewrote the MemoryTransport to be similar to the TcpConfig.

• Added NetworkBehaviour::inject_replaced that is called whenever we replace a connection with a different connection to the same peer.
• Fixed various issues with Kademlia.

• Removed the topology module and everything it contained, including the Topology trait.
• Added libp2p-noise that supports Noise handshakes, as an alternative to libp2p-secio.
• Updated ring to version 0.14.
• Creating a Swarm now expects the PeerId of the local node, instead of a Topology.
• Added NetworkBehaviour::addresses_of_peer that returns the addresses a NetworkBehaviour knows about a given peer. This exists as a replacement for the topology.
• The Kademlia and Mdns behaviours now report and store the list of addresses they discover.
• You must now call Floodsub::add_node_to_partial_view() and Floodsub::remove_node_from_partial_view to add/remove nodes from the list of nodes that floodsub must send messages to.
• Added NetworkBehaviour::inject_dial_failure that is called when we fail to dial an address.
• ProtocolsHandler::connection_keep_alive() now returns a KeepAlive enum that provides more fine grained control.
• The NodeHandlerWrapper no longer has a 5 seconds inactivity timeout. This is now handled entirely by ProtocolsHandler::connection_keep_alive().
• Now properly denying connections incoming from the same PeerId as ours.
• Added a SwarmBuilder. The incoming_limit method lets you configure the number of simultaneous incoming connections.
• Removed FloodsubHandler, PingListenHandler and PeriodicPingHandler.
• The structs in core::nodes are now generic over the PeerId.
• Added SecioKeypair::ed25519_raw_key().
• Fix improper connection shutdown in ProtocolsHandler.

• Fixed improper dependencies versions causing deriving NetworkBehaviour to generate an error.

• Added the IntoNodeHandler and IntoProtocolsHandler traits, allowing node handlers and protocol handlers to know the PeerId of the node they are interacting with.