libp2p-swarm

• Remove async-std support. See PR 6074

• Remove once_cell dependency. See PR 5913

• Separate the PendingConnectionError into two parts PendingOutboundConnectionError and PendingInboundConnectionError to have better control over error handling. See PR

• Undo ConnectionHandler::{InboundOpenInfo, OutboundOpenInfo} deprecation. Substreams are not completely interchangeable and a certain Substream may be associated with a certain upgrade. See PR 5860.

• Expose Option<PeerId> in SwarmEvent::IncomingConnectionError. This enables insight to which PeerId errored. See PR 6032

• Don't report NewExternalAddrCandidate for confirmed external addresses. See PR 5582.

• Deprecate void crate. See PR 5676.

• Fix cargo clippy warnings in rustc 1.84.0-beta.1. See PR 5700.

• Update default for idle-connection-timeout to 10s. See PR 4967.

• Deprecate ConnectionHandler::{InboundOpenInfo, OutboundOpenInfo} associated type. Previously, users could tag pending sub streams with custom data and retrieve the data after the substream has been negotiated. But substreams themselves are completely interchangeable, users should instead track additional data inside ConnectionHandler after negotiation. See PR 5242.

<!-- Update to libp2p-core v0.43.0 -->

• Update libp2p-swarm-derive to version 0.35.0, see PR 5545

• Implement refactored Transport. See PR 4568
• Move address_translation into swarm and into libp2p-identify. See PR 4568

• Allow NetworkBehaviours to share addresses of peers. This is enabled via the new ToSwarm::NewExternalAddrOfPeer event. The address is broadcast to all behaviours via FromSwarm::NewExternalAddrOfPeer. Protocols that want to collect these addresses can use the new PeerAddresses utility. See PR 4371.

• Implement Clone & Copy for `FromSwarm. This makes it easier to forward these events when wrapping other behaviours. See PR 4825.

• Add #[non_exhaustive] to FromSwarm, ToSwarm, SwarmEvent, ConnectionHandlerEvent, ConnectionEvent. See PR 4581.
• Remove handler field from ConnectionClosed. If you need to transfer state from a ConnectionHandler to its NetworkBehaviour when a connection closes, use ConnectionHandler::poll_close. See PR 4076.
• Remove deprecated PollParameters from NetworkBehaviour::poll function. See PR 4490.
• Remove deprecated ConnectionHandlerEvent::Close and ConnectionHandler::Error. ConnectionHandlers should not close connections directly as the connection might still be in use by other handlers. See PR 4755.
• Add PeerCondition::DisconnectedAndNotDialing variant, combining pre-existing conditions. This is the new default. A new dialing attempt is initiated only if the peer is both considered disconnected and there is currently no ongoing dialing attempt. See PR 4225.
• Remove deprecated keep_alive_timeout in OneShotHandlerConfig. See PR 4677.
• Don't close entire connection upon DialUpgradeErrors within OneShotHandler. Instead, the error is reported as Err(e) via ConnectionHandler::ToBehaviour. See PR 4715.
• Log PeerId of Swarm even when constructed with new SwarmBuilder. See PR 4671.
• Add SwarmEvent::{NewExternalAddrCandidate,ExternalAddrConfirmed,ExternalAddrExpired} variants. See PR 4721.
• Remove deprecated symbols. See PR 4737.

• Deprecate ConnectionHandlerEvent::Close. See issue 3591 for details. See PR 4714.

• Deprecate libp2p::swarm::SwarmBuilder. Most users should use libp2p::SwarmBuilder. In some special cases, users may need to use Swarm::new and Config instead of the new libp2p::SwarmBuilder. See PR 4120.
• Make the Debug implementation of StreamProtocol more concise. See PR 4631.
• Fix overflow in KeepAlive computation that could occur panic at Delay::new if SwarmBuilder::idle_connection_timeout is configured too large. See PR 4644.
• Deprecate KeepAlive::Until. Individual protocols should not keep connections alive for longer than necessary. Users should use swarm::Config::idle_connection_timeout instead. See PR 4656.
• Deprecate keep_alive_timeout in OneShotHandlerConfig. See PR 4680.

• Fix overflow in KeepAlive computation that could occur if SwarmBuilder::idle_connection_timeout is configured with u64::MAX. See PR 4559.

• Implement Debug for event structs. See PR 4426.

• Improve error message when DialPeerCondition prevents a dial. See PR 4409.

• Introduce SwarmBuilder::idle_connection_timeout and deprecate keep_alive::Behaviour as a result. See PR 4161.

• Implement Display for ConnectionId. See PR 4278.

• Display the cause of a ListenError::Denied. See PR 4232

• Do not announce external address candidate before address translation, unless translation does not apply. This will prevent ephemeral TCP addresses being announced as external address candidates. See PR 4158.

• Allow NetworkBehaviours to create and remove listeners. See PR 3292.

• Raise MSRV to 1.65. See PR 3715.

• Introduce StreamProtocol type. This type enforces invariants on protocol names, such as leading forward slashes and correct UTF8 encoding. See PR 3746.

• Return a bool from ExternalAddresses::on_swarm_event and ListenAddresses::on_swarm_event indicating whether any state was changed. See PR 3865.

• Remove deprecated banning API from Swarm. Users should migrate to libp2p::allow_block_list. See PR 3886.

• Remove ConnectionHandlerUpgrErr::Timer variant. This variant was never constructed and thus dead code. See PR 3605.

• Remove deprecated IntoConnectionHandler and all its implementations. This also removes the NetworkBehaviour::new_handler and NetworkBehaviour::addresses_of_peer methods. See changelog for 0.42 on how to migrate. See PR 3884.

• Remove ConnectionHandlerUpgrErr::Timer variant. This variant was never constructed and thus dead code. See PR 3605.

• Flatten ConnectionHandlerUpgrErr and rename to StreamUpgradeError. See PR 3882.

• Remove deprecated ConnectionLimits. Users should migrate to libp2p::connection_limits::Behaviour. See PR 3885.

• Allow ConnectionHandlers to report and learn about the supported protocols on a connection. The newly introduced API elements are:

  • ConnectionHandlerEvent::ReportRemoteProtocols
  • ConnectionEvent::LocalProtocolsChange
  • ConnectionEvent::RemoteProtocolsChange

  See PR 3651.

• Deprecate the NegotiatedSubstream type and replace it with Stream. See PR 3912.

• Rename NetworkBehaviour::OutEvent to NetworkBehaviour::ToSwarm, ConnectionHandler::InEvent to ConnectionHandler::FromBehaviour, ConnectionHandler::OutEvent to ConnectionHandler::ToBehaviour. See PR 3848.

• Remove deprecated NetworkBehaviourAction type. See PR 3919.

• Expose ConnectionId on SwarmEvent::{ConnectionEstablished,ConnectionClosed,IncomingConnection,IncomingConnectionError,OutgoingConnectionError,Dialing}. Also emit SwarmEvent::Dialing for dials with unknown PeerId. See PR 3927.

• Rename ConnectionHandlerEvent::Custom to ConnectionHandlerEvent::NotifyBehaviour. See PR 3955.

• Remove DialError::InvalidPeerId variant. With the move to multiaddr v0.18.0 peer IDs in /p2p are type safe and thus usage of the contained peer ID can not result in a parsing error. See PR 4037.

• Remove deprecated items. See PR 3956.

• Add ability to downcast_ref ConnectionDenied errors. See PR 4020.

• Add ConnectionEvent::{is_outbound,is_inbound}. See PR 3625.

• Deprecate ConnectionLimits in favor of libp2p::connection_limits. See PR 3386.

• Introduce ConnectionId::new_unchecked to allow for more sophisticated, manual tests of NetworkBehaviour. See PR 3652.

• Deprecate Swarm::ban_peer_id in favor of the new libp2p::allow_block_list module. See PR 3590.

• Rename NetworkBehaviourAction to ToSwarm. A deprecated type-alias is provided to ease the transition. The new name is meant to better indicate the message-passing relationship between Swarm and NetworkBehaviour. See PR 3658.

• Allow NetworkBehaviours to manage connections. We deprecate NetworkBehaviour::new_handler and NetworkBehaviour::addresses_of_peer in favor of four new callbacks:

  • NetworkBehaviour::handle_pending_inbound_connection
  • NetworkBehaviour::handle_pending_outbound_connection
  • NetworkBehaviour::handle_established_inbound_connection
  • NetworkBehaviour::handle_established_outbound_connection

  Please note that due to limitations in the Rust compiler, implementations of new_handler and addresses_of_peer are not flagged as deprecated. Nevertheless, they will be removed in the future.

  All four are fallible and returning an error from any of them will abort the given connection. This allows you to create dedicated NetworkBehaviours that only concern themselves with managing connections. For example:

  • checking the PeerId of a newly established connection against an allow/block list
  • only allowing X connection upgrades at any one time
  • denying incoming or outgoing connections from a certain IP range
  • only allowing N connections to or from the same peer

  See PR 3254.

• Remove handler field from NetworkBehaviourAction::Dial. Instead of constructing the handler early, you can now access the ConnectionId of the future connection on DialOpts. ConnectionIds are Copy and will be used throughout the entire lifetime of the connection to report events. This allows you to send events to a very specific connection, much like you previously could directly set state in the handler.

  Removing the handler field also reduces the type parameters of NetworkBehaviourAction from three to two. The third one used to be defaulted to the InEvent of the ConnectionHandler. You now have to manually specify that where you previously had to specify the ConnectionHandler. This very likely will trigger convoluted compile errors about traits not being implemented.

  Within NetworkBehaviourAction::poll, the easiest way to migrate is to do this (in the example of libp2p-floodsub):

  --- a/protocols/floodsub/src/layer.rs
  +++ b/protocols/floodsub/src/layer.rs
  @@ -472,7 +465,7 @@ impl NetworkBehaviour for Floodsub {
       &mut self,
       _: &mut Context<'_>,
       _: &mut impl PollParameters,
  -    ) -> Poll<NetworkBehaviourAction<Self::OutEvent, Self::ConnectionHandler>> {
  +    ) -> Poll<NetworkBehaviourAction<Self::OutEvent, THandlerInEvent<Self>>> {
  

  In other words:

  Search	Replace
  NetworkBehaviourAction<Self::OutEvent, Self::ConnectionHandler>	NetworkBehaviourAction<Self::OutEvent, THandlerInEvent<Self>>

  If you reference NetworkBehaviourAction somewhere else as well, you may have to fill in the type of ConnectionHandler::InEvent manually as the 2nd parameter.

  See PR 3328.

• Update to libp2p-core v0.39.0.

• Removed deprecated Swarm constructors. For transition notes see 0.41.0. See PR 3170.

• Deprecate functions on PollParameters in preparation for PollParameters to be removed entirely eventually. See PR 3153.

• Add estblished_in to SwarmEvent::ConnectionEstablished. See PR 3134.

• Remove deprecated inject_* methods from NetworkBehaviour and ConnectionHandler. Make the implementation of on_swarm_event and on_connection_handler_event both mandatory. See PR 3264 and PR 3364.

• Update to libp2p-swarm-derive v0.32.0.

• Replace SwarmBuilder::connection_event_buffer_size with SwarmBuilder::per_connection_event_buffer_size . The configured value now applies per connection. The default values remains 7. If you have previously set connection_event_buffer_size you should re-evaluate what a good size for a per connection buffer is. See PR 3188.

• Remove DialError::ConnectionIo variant. This was never constructed. See PR 3374.

• Introduce ListenError and use it within SwarmEvent::IncomingConnectionError. See PR 3375.

• Remove PendingConnectionError, PendingInboundConnectionError and PendingOutboundConnectionError from the public API. They are no longer referenced anywhere with the addition of ListenError. See PR 3497.

• Remove ConnectionId::new. Manually creating ConnectionIds is now unsupported. See PR 3327.

• Deprecate methods Swarm::with_executor, Swarm::with_*_executor, Swarm::without_executor. Introduce similar methods in SwarmBuilder. See PR 3588.

• Gracefully disable oneshot handler on dial upgrade errors. See PR 3577.

• Update to libp2p-swarm-derive v0.31.0.

• Update to libp2p-core v0.38.0.

• Add new on_connection_event method to ConnectionHandler that accepts a ConnectionEvent enum and update inject_* methods to call on_connection_event with the respective ConnectionEvent variant and deprecate inject_*. To migrate, users should replace the ConnectionHandler::inject_* calls with a single implementation of ConnectionHandler::on_connection_event treating each ConnectionEvent variant in the same way its corresponding inject_* call was treated. See PR 3085.

• Add new on_behaviour_event method with the same signature as inject_event, make the default implementation of inject_event call on_behaviour_event and deprecate it. To migrate, users should replace the ConnectionHandler::inject_event call with ConnectionHandler::on_behaviour_event. See PR 3085.

• Add new on_swarm_event method to NetworkBehaviour that accepts a FromSwarm enum and update inject_* methods to call on_swarm_event with the respective FromSwarm variant and deprecate inject_*. To migrate, users should replace the NetworkBehaviour::inject_* calls with a single implementation of NetworkBehaviour::on_swarm_event treating each FromSwarm variant in the same way its corresponding inject_* call was treated. See PR 3011.

• Add new on_connection_handler_event method with the same signature as inject_event, make the default implementation of inject_event call on_connection_handler_event and deprecate it. To migrate, users should replace the NetworkBehaviour::inject_event call with NetworkBehaviour::on_connection_handler_event. See PR 3011.

• Export NetworkBehaviour derive as libp2p_swarm::NetworkBehaviour. This follows the convention of other popular libraries. serde for example exports the Serialize trait and macro as serde::Serialize. See PR 3055.

• Feature-gate NetworkBehaviour macro behind macros feature flag. See PR 3055.

• Make executor in Swarm constructor explicit. See PR 3097.

  Supported executors:

  • Tokio

    Previously

    let swarm = SwarmBuilder::new(transport, behaviour, peer_id)
        .executor(Box::new(|fut| {
                tokio::spawn(fut);
        }))
        .build();
    

    Now

    let swarm = Swarm::with_tokio_executor(transport, behaviour, peer_id);
    

  • Async Std

    Previously

    let swarm = SwarmBuilder::new(transport, behaviour, peer_id)
        .executor(Box::new(|fut| {
                async_std::task::spawn(fut);
        }))
        .build();
    

    Now

    let swarm = Swarm::with_async_std_executor(transport, behaviour, peer_id);
    

  • ThreadPool (see Issue 3107)

    In most cases ThreadPool can be replaced by executors or spawning on the local task.

    Previously

    let swarm = Swarm::new(transport, behaviour, peer_id);
    

    Now

    let swarm = Swarm::with_threadpool_executor(transport, behaviour, peer_id);
    

  • Without

    Spawns the tasks on the current task, this may result in bad performance so try to use an executor where possible. Previously this was just a fallback when no executor was specified and constructing a ThreadPool failed.

    New

    let swarm = Swarm::without_executor(transport, behaviour, peer_id);
    

  Deprecated APIs:

  • Swarm::new
  • SwarmBuilder::new
  • SwarmBuilder::executor

• Update rust-version to reflect the actual MSRV: 1.62.0. See PR 3090.

• Bump rand to 0.8 and quickcheck to 1. See PR 2857.

• Update to libp2p-core v0.37.0.

• Introduce libp2p_swarm::keep_alive::ConnectionHandler in favor of removing keep_alive from libp2p_swarm::dummy::ConnectionHandler. dummy::ConnectionHandler now literally does not do anything. In the same spirit, introduce libp2p_swarm::keep_alive::Behaviour and libp2p_swarm::dummy::Behaviour. See PR 2859.

• Pass actual PeerId of dial to NetworkBehaviour::inject_dial_failure on DialError::ConnectionLimit. See PR 2928.

• Remove deprecated NetworkBehaviourEventProcess. See libp2p-swarm v0.38.0 changelog entry for migration path.

• Update to libp2p-core v0.36.0.

• Enforce backpressure on incoming streams via StreamMuxer interface. In case we hit the configured limit of maximum number of inbound streams, we will stop polling the StreamMuxer for new inbound streams. Depending on the muxer implementation in use, this may lead to instant dropping of inbound streams. See PR 2861.

• Deprecate NetworkBehaviourEventProcess. When deriving NetworkBehaviour on a custom struct users should either bring their own OutEvent via #[behaviour(out_event = "MyBehaviourEvent")] or, when not specified, have the derive macro generate one for the user.

  See NetworkBehaviour documentation and PR 2784 for details.

  Previously

  #[derive(NetworkBehaviour)]
  #[behaviour(event_process = true)]
  struct MyBehaviour {
      gossipsub: Gossipsub,
      mdns: Mdns,
  }
  
  impl NetworkBehaviourEventProcess<Gossipsub> for MyBehaviour {
      fn inject_event(&mut self, message: GossipsubEvent) {
        todo!("Handle event")
      }
  }
  
  impl NetworkBehaviourEventProcess<MdnsEvent> for MyBehaviour {
      fn inject_event(&mut self, message: MdnsEvent) {
        todo!("Handle event")
      }
  }
  

  Now

  #[derive(NetworkBehaviour)]
  #[behaviour(out_event = "MyBehaviourEvent")]
  struct MyBehaviour {
      gossipsub: Gossipsub,
      mdns: Mdns,
  }
  
  enum MyBehaviourEvent {
      Gossipsub(GossipsubEvent),
      Mdns(MdnsEvent),
  }
  
  impl From<GossipsubEvent> for MyBehaviourEvent {
      fn from(event: GossipsubEvent) -> Self {
          MyBehaviourEvent::Gossipsub(event)
      }
  }
  
  impl From<MdnsEvent> for MyBehaviourEvent {
      fn from(event: MdnsEvent) -> Self {
          MyBehaviourEvent::Mdns(event)
      }
  }
  
  match swarm.next().await.unwrap() {
    SwarmEvent::Behaviour(MyBehaviourEvent::Gossipsub(event)) => {
      todo!("Handle event")
    }
    SwarmEvent::Behaviour(MyBehaviourEvent::Mdns(event)) => {
      todo!("Handle event")
    }
  }
  

• When deriving NetworkBehaviour on a custom struct where the user does not specify their own OutEvent via #[behaviour(out_event = "MyBehaviourEvent")] and where the user does not enable #[behaviour(event_process = true)], then the derive macro generates an OutEvent definition for the user.

  See NetworkBehaviour documentation and PR 2792 for details.

• Update dial address concurrency factor to 8, thus dialing up to 8 addresses concurrently for a single connection attempt. See Swarm::dial_concurrency_factor and PR 2741.

• Update to libp2p-core v0.35.0.

• Update to libp2p-core v0.34.0.

• Extend log message when exceeding inbound negotiating streams with peer ID and limit. See PR 2716.

• Remove connection::ListenersStream and poll the Transport directly. See PR 2652.

• Limit negotiating inbound substreams per connection. See PR 2697.

• Don't require Transport to be Clone. See PR 2529.

• Update to libp2p-core v0.33.0.

• Make behaviour::either module private. See PR 2610

• Rename IncomingInfo::to_connected_point to IncomingInfo::create_connected_point. See PR 2620.

• Rename TProtoHandler to TConnectionHandler, ToggleProtoHandler to ToggleConnectionHandler, ToggleIntoProtoHandler to ToggleIntoConnectionHandler. See PR 2640.

• Add impl IntoIterator for MultiHandler. See PR 2572.
• Remove Send bound from NetworkBehaviour. See PR 2535.

• Rename ProtocolsHandler to ConnectionHandler. Upgrade should be as simple as renaming all occurrences of ProtocolsHandler to ConnectionHandler with your favorite text manipulation tool across your codebase. See PR 2527.

• Fold libp2p-core's Network into Swarm. See PR 2492.

• Update to libp2p-core v0.32.0.

• Disconnect pending connections with Swarm::disconnect. See PR 2517.

• Report aborted connections via SwarmEvent::OutgoingConnectionError. See PR 2517.

• Patch reporting on banned peers and their non-banned and banned connections (see PR 2350).

• Update dependencies.

• Migrate to Rust edition 2021 (see PR 2339).

• Update Connection::address on inject_address_change (see PR 2362).

• Move swarm::Toggle to swarm::behaviour::Toggle (see PR 2375).

• Add Swarm::connected_peers (see PR 2378).

• Implement swarm::NetworkBehaviour on either::Either (see PR 2370).

• Allow overriding dial concurrency factor per dial via DialOpts::override_dial_concurrency_factor. See PR 2404.

• Report negotiated and expected PeerId as well as remote address in DialError::WrongPeerId (see PR 2428).

• Allow overriding role when dialing through override_role option on DialOpts. This option is needed for NAT and firewall hole punching. See PR 2363.

• Merge NetworkBehaviour's inject_* paired methods (see PR 2445).

• Use instant and futures-timer instead of wasm-timer (see PR 2245).

• Enable advanced dialing requests both on Swarm::dial and via NetworkBehaviourAction::Dial. Users can now trigger a dial with a specific set of addresses, optionally extended via NetworkBehaviour::addresses_of_peer.

  Changes required to maintain status quo:

  • Previously swarm.dial(peer_id) now swarm.dial(DialOpts::peer_id(peer_id).build()) or swarm.dial(peer_id) given that DialOpts implements From<PeerId>.

  • Previously swarm.dial_addr(addr) now swarm.dial(DialOpts::unknown_peer_id().address(addr).build()) or swarm.dial(addr) given that DialOpts implements From<Multiaddr>.

  • Previously NetworkBehaviourAction::DialPeer { peer_id, condition, handler } now

    NetworkBehaviourAction::Dial {
      opts: DialOpts::peer_id(peer_id)
        .condition(condition)
        .build(),
      handler,
    }
    

  • Previously NetworkBehaviourAction::DialAddress { address, handler } now

    NetworkBehaviourAction::Dial {
      opts: DialOpts::unknown_peer_id()
        .address(address)
        .build(),
      handler,
    }
    

  See PR 2317.

• Make default features of libp2p-core optional. PR 2181

• Update dependencies.

• Provide default implementations for all functions of NetworkBehaviour, except for new_handler, inject_event and poll. This should make it easier to create new implementations. See PR 2150.

• Remove Swarm type alias and rename ExpandedSwarm to Swarm. Reduce direct trait parameters on Swarm (previously ExpandedSwarm), deriving parameters through associated types on TBehaviour. See PR 2182.

• Require ProtocolsHandler::{InEvent,OutEvent,Error} to implement Debug (see PR 2183).

• Implement ProtocolsHandler on either::Eitherrepresenting either of two ProtocolsHandler implementations (see PR 2192).

• Require implementation to provide handler in NetworkBehaviourAction::DialPeer and NetworkBehaviourAction::DialAddress. Note that the handler is returned to the NetworkBehaviour on connection failure and connection closing. Thus it can be used to carry state, which otherwise would have to be tracked in the NetworkBehaviour itself. E.g. a message destined to an unconnected peer can be included in the handler, and thus directly send on connection success or extracted by the NetworkBehaviour on connection failure (see PR 2191).

• Include handler in NetworkBehaviour::inject_dial_failure, NetworkBehaviour::inject_connection_closed, NetworkBehaviour::inject_listen_failure (see PR 2191).

• Include error in NetworkBehaviour::inject_dial_failure and call NetworkBehaviour::inject_dial_failure on DialPeerCondition evaluating to false. To emulate the previous behaviour, return early within inject_dial_failure on DialError::DialPeerConditionFalse. See PR 2191.

• Make NetworkBehaviourAction generic over NetworkBehaviour::OutEvent and NetworkBehaviour::ProtocolsHandler. In most cases, change your generic type parameters to NetworkBehaviourAction<Self::OutEvent, Self::ProtocolsHandler>. See PR 2191.

• Return bool instead of Result<(), ()> for Swarm::remove_listener(see PR 2261).

• Concurrently dial address candidates within a single dial attempt (see PR 2248) configured via Swarm::dial_concurrency_factor.

  • On success of a single address, report errors of the thus far failed dials via SwarmEvent::ConnectionEstablished::outgoing.

  • On failure of all addresses, report errors via the new SwarmEvent::OutgoingConnectionError.

  • Remove SwarmEvent::UnreachableAddr and SwarmEvent::UnknownPeerUnreachableAddr event.

  • In NetworkBehaviour::inject_connection_established provide errors of all thus far failed addresses.

  • On unknown peer dial failures, call NetworkBehaviour::inject_dial_failure with a peer ID of None.

  • Remove NetworkBehaviour::inject_addr_reach_failure. Information is now provided via NetworkBehaviour::inject_connection_established and NetworkBehaviour::inject_dial_failure.

• Update dependencies.

• Drive ExpandedSwarm via Stream trait only.

  • Change Stream implementation of ExpandedSwarm to return all SwarmEvents instead of only the NetworkBehaviour's events.

  • Remove ExpandedSwarm::next_event. Users can use <ExpandedSwarm as StreamExt>::next instead.

  • Remove ExpandedSwarm::next. Users can use <ExpandedSwarm as StreamExt>::filter_map instead.

  See PR 2100 for details.

• Add ExpandedSwarm::disconnect_peer_id and NetworkBehaviourAction::CloseConnection to close connections to a specific peer via an ExpandedSwarm or NetworkBehaviour. See PR 2110 for details.

• Expose the ListenerId in SwarmEvents that are associated with a listener.

  See PR 2123 for details.

• Remove Deref and DerefMut implementations previously dereferencing to the NetworkBehaviour on Swarm. Instead one can access the NetworkBehaviour via Swarm::behaviour and Swarm::behaviour_mut. Methods on Swarm can now be accessed directly, e.g. via my_swarm.local_peer_id(). You may use the command below to transform fully qualified method calls on Swarm to simple method calls PR 1995.

  # Go from e.g. `Swarm::local_peer_id(&my_swarm)` to `my_swarm.local_peer_id()`.
  grep -RiIl --include \*.rs --exclude-dir target . --exclude-dir .git | xargs sed -i "s/\(libp2p::\)*Swarm::\([a-z_]*\)(&mut \([a-z_0-9]*\), /\3.\2(/g"
  

• Extend NetworkBehaviour callbacks, more concretely introducing new fn inject_new_listener and fn inject_expired_external_addr and have fn inject_{new,expired}_listen_addr provide a ListenerId PR 2011.

• New error variant DialError::InvalidAddress

• Swarm::dial_addr() now returns a DialError on error.

• Remove the option for a substream-specific multistream select protocol override. The override at this granularity is no longer deemed useful, in particular because it can usually not be configured for existing protocols like libp2p-kad and others. There is a Swarm-scoped configuration for this version available since 1858.

• Have ToggleProtoHandler ignore listen upgrade errors when disabled. PR 1945.

• Make OneShotHandlers max_dial_negotiate limit configurable. PR 1936.

• Fix handling of DialPeerCondition::Always. PR 1937.

• Update dependencies.

• Update libp2p-core.

• Remove NotifyHandler::All thus removing the requirement for events send from a NetworkBehaviour to a ProtocolsHandler to be Clone. PR 1880.

• Add ExpandedSwarm::is_connected. PR 1862.

• Permit a configuration override for the substream upgrade protocol to use for all (outbound) substreams. PR 1858.

• Changed parameters for connection limits from usize to u32. Connection limits are now configured via SwarmBuilder::connection_limits().

• Update libp2p-core.

• Expose configurable scores for external addresses, as well as the ability to remove them and to add addresses that are retained "forever" (or until explicitly removed). PR 1842.

• Update dependencies.

• Require a Boxed transport to be given to the Swarm or SwarmBuilder to avoid unnecessary double-boxing of transports and simplify API bounds. PR 1794

• Respect inbound timeouts and upgrade versions in the MultiHandler. PR 1786.

• Instead of iterating each inbound and outbound substream upgrade looking for one to make progress, use a FuturesUnordered for both pending inbound and pending outbound upgrades. As a result only those upgrades are polled that are ready to progress.

  Implementers of InboundUpgrade and OutboundUpgrade need to ensure to wake up the underlying task once they are ready to make progress as they won't be polled otherwise.

  PR 1775

• Bump libp2p-core dependency.

• Adds ProtocolsHandler::InboundOpenInfo type which mirrors the existing OutboundOpenInfo type. A value of this type is passed as an extra argument to ProtocolsHandler::inject_fully_negotiated_inbound and ProtocolsHandler::inject_listen_upgrade_error.

• SubstreamProtocol now has a second type parameter corresponding to inbound or outbound information, a value of which is part of SubstreamProtocol now. Consequently ProtocolsHandlerEvent::OutboundSubstreamRequest no longer has a separate info field.

• Add missing delegation calls in some ProtocolsHandler wrappers. See PR 1710.

• Add as_ref and as_mut functions to Toggle PR 1684.

• The cause of SwarmEvent::ConnectionClosed is now an Option, and None indicates an active connection close not caused by an error.

• DialError::Banned has been added and is returned from Swarm::dial if the peer is banned, thereby also invoking the NetworkBehaviour::inject_dial_failure callback.

• Update the libp2p-core dependency to 0.21, fixing 1584.

• Fix connections being kept alive by OneShotHandler when not handling any requests PR 1698.

• Documentation updates.

• Ignore addresses returned by NetworkBehaviour::addresses_of_peer that the Swarm considers to be listening addresses of the local node. This avoids futile dialing attempts of a node to itself, which can otherwise even happen in genuine situations, e.g. after the local node changed its network identity and a behaviour makes a dialing attempt to a former identity using the same addresses.

• Updated the libp2p-core dependency.

• Add ProtocolsHandler::inject_listen_upgrade_error, the inbound analogue of ProtocolsHandler::inject_dial_upgrade_error, with an empty default implementation. No implementation is required to retain existing behaviour.

• Add ProtocolsHandler::inject_address_change and NetworkBehaviour::inject_address_change to notify of a change in the address of an existing connection.

• Bugfix: Fix MultiHandler panicking when empty (PR 1598).