maybemaybe

rust/networking/src/discovery.rs

@@ -1,382 +0,0 @@
-use crate::ext::MultiaddrExt;
-use delegate::delegate;
-use either::Either;
-use futures_lite::FutureExt;
-use futures_timer::Delay;
-use libp2p::core::transport::PortUse;
-use libp2p::core::{ConnectedPoint, Endpoint};
-use libp2p::swarm::behaviour::ConnectionEstablished;
-use libp2p::swarm::dial_opts::DialOpts;
-use libp2p::swarm::{
-    CloseConnection, ConnectionClosed, ConnectionDenied, ConnectionHandler,
-    ConnectionHandlerSelect, ConnectionId, FromSwarm, NetworkBehaviour, THandler, THandlerInEvent,
-    THandlerOutEvent, ToSwarm, dummy,
-};
-use libp2p::{Multiaddr, PeerId, identity, mdns};
-use std::collections::{BTreeSet, HashMap};
-use std::convert::Infallible;
-use std::io;
-use std::net::IpAddr;
-use std::task::{Context, Poll};
-use std::time::Duration;
-use util::wakerdeque::WakerDeque;
-
-const RETRY_CONNECT_INTERVAL: Duration = Duration::from_secs(5);
-
-mod managed {
-    use libp2p::swarm::NetworkBehaviour;
-    use libp2p::{identity, mdns, ping};
-    use std::io;
-    use std::time::Duration;
-
-    const MDNS_RECORD_TTL: Duration = Duration::from_secs(2_500);
-    const MDNS_QUERY_INTERVAL: Duration = Duration::from_secs(1_500);
-    const PING_TIMEOUT: Duration = Duration::from_millis(2_500);
-    const PING_INTERVAL: Duration = Duration::from_millis(2_500);
-
-    #[derive(NetworkBehaviour)]
-    pub struct Behaviour {
-        mdns: mdns::tokio::Behaviour,
-        ping: ping::Behaviour,
-    }
-
-    impl Behaviour {
-        pub fn new(keypair: &identity::Keypair) -> io::Result<Self> {
-            Ok(Self {
-                mdns: mdns_behaviour(keypair)?,
-                ping: ping_behaviour(),
-            })
-        }
-    }
-
-    fn mdns_behaviour(keypair: &identity::Keypair) -> io::Result<mdns::tokio::Behaviour> {
-        use mdns::{Config, tokio};
-
-        // mDNS config => enable IPv6
-        let mdns_config = Config {
-            ttl: MDNS_RECORD_TTL,
-            query_interval: MDNS_QUERY_INTERVAL,
-
-            // enable_ipv6: true, // TODO: for some reason, TCP+mDNS don't work well with ipv6?? figure out how to make work
-            ..Default::default()
-        };
-
-        let mdns_behaviour = tokio::Behaviour::new(mdns_config, keypair.public().to_peer_id());
-        Ok(mdns_behaviour?)
-    }
-
-    fn ping_behaviour() -> ping::Behaviour {
-        ping::Behaviour::new(
-            ping::Config::new()
-                .with_timeout(PING_TIMEOUT)
-                .with_interval(PING_INTERVAL),
-        )
-    }
-}
-
-/// Events for when a listening connection is truly established and truly closed.
-#[derive(Debug, Clone)]
-pub enum Event {
-    ConnectionEstablished {
-        peer_id: PeerId,
-        connection_id: ConnectionId,
-        remote_ip: IpAddr,
-        remote_tcp_port: u16,
-    },
-    ConnectionClosed {
-        peer_id: PeerId,
-        connection_id: ConnectionId,
-        remote_ip: IpAddr,
-        remote_tcp_port: u16,
-    },
-}
-
-/// Discovery behavior that wraps mDNS to produce truly discovered durable peer-connections.
-///
-/// The behaviour operates as such:
-///  1) All true (listening) connections/disconnections are tracked, emitting corresponding events
-///     to the swarm.
-///  1) mDNS discovered/expired peers are tracked; discovered but not connected peers are dialed
-///     immediately, and expired but connected peers are disconnected from immediately.
-///  2) Every fixed interval: discovered but not connected peers are dialed, and expired but
-///     connected peers are disconnected from.
-pub struct Behaviour {
-    // state-tracking for managed behaviors & mDNS-discovered peers
-    managed: managed::Behaviour,
-    mdns_discovered: HashMap<PeerId, BTreeSet<Multiaddr>>,
-
-    retry_delay: Delay, // retry interval
-
-    // pending events to emmit => waker-backed Deque to control polling
-    pending_events: WakerDeque<ToSwarm<Event, Infallible>>,
-}
-
-impl Behaviour {
-    pub fn new(keypair: &identity::Keypair) -> io::Result<Self> {
-        Ok(Self {
-            managed: managed::Behaviour::new(keypair)?,
-            mdns_discovered: HashMap::new(),
-            retry_delay: Delay::new(RETRY_CONNECT_INTERVAL),
-            pending_events: WakerDeque::new(),
-        })
-    }
-
-    fn dial(&mut self, peer_id: PeerId, addr: Multiaddr) {
-        self.pending_events.push_back(ToSwarm::Dial {
-            opts: DialOpts::peer_id(peer_id).addresses(vec![addr]).build(),
-        })
-    }
-
-    fn close_connection(&mut self, peer_id: PeerId, connection: ConnectionId) {
-        // push front to make this IMMEDIATE
-        self.pending_events.push_front(ToSwarm::CloseConnection {
-            peer_id,
-            connection: CloseConnection::One(connection),
-        })
-    }
-
-    fn handle_mdns_discovered(&mut self, peers: Vec<(PeerId, Multiaddr)>) {
-        for (p, ma) in peers {
-            self.dial(p, ma.clone()); // always connect
-
-            // get peer's multi-addresses or insert if missing
-            let Some(mas) = self.mdns_discovered.get_mut(&p) else {
-                self.mdns_discovered.insert(p, BTreeSet::from([ma]));
-                continue;
-            };
-
-            // multiaddress should never already be present - else something has gone wrong
-            let is_new_addr = mas.insert(ma);
-            assert!(is_new_addr, "cannot discover a discovered peer");
-        }
-    }
-
-    fn handle_mdns_expired(&mut self, peers: Vec<(PeerId, Multiaddr)>) {
-        for (p, ma) in peers {
-            // at this point, we *must* have the peer
-            let mas = self
-                .mdns_discovered
-                .get_mut(&p)
-                .expect("nonexistent peer cannot expire");
-
-            // at this point, we *must* have the multiaddress
-            let was_present = mas.remove(&ma);
-            assert!(was_present, "nonexistent multiaddress cannot expire");
-
-            // if empty, remove the peer-id entirely
-            if mas.is_empty() {
-                self.mdns_discovered.remove(&p);
-            }
-        }
-    }
-
-    fn on_connection_established(
-        &mut self,
-        peer_id: PeerId,
-        connection_id: ConnectionId,
-        remote_ip: IpAddr,
-        remote_tcp_port: u16,
-    ) {
-        // send out connected event
-        self.pending_events
-            .push_back(ToSwarm::GenerateEvent(Event::ConnectionEstablished {
-                peer_id,
-                connection_id,
-                remote_ip,
-                remote_tcp_port,
-            }));
-    }
-
-    fn on_connection_closed(
-        &mut self,
-        peer_id: PeerId,
-        connection_id: ConnectionId,
-        remote_ip: IpAddr,
-        remote_tcp_port: u16,
-    ) {
-        // send out disconnected event
-        self.pending_events
-            .push_back(ToSwarm::GenerateEvent(Event::ConnectionClosed {
-                peer_id,
-                connection_id,
-                remote_ip,
-                remote_tcp_port,
-            }));
-    }
-}
-
-impl NetworkBehaviour for Behaviour {
-    type ConnectionHandler =
-        ConnectionHandlerSelect<dummy::ConnectionHandler, THandler<managed::Behaviour>>;
-    type ToSwarm = Event;
-
-    // simply delegate to underlying mDNS behaviour
-
-    delegate! {
-        to self.managed {
-            fn handle_pending_inbound_connection(&mut self, connection_id: ConnectionId, local_addr: &Multiaddr, remote_addr: &Multiaddr) -> Result<(), ConnectionDenied>;
-            fn handle_pending_outbound_connection(&mut self, connection_id: ConnectionId, maybe_peer: Option<PeerId>, addresses: &[Multiaddr], effective_role: Endpoint) -> Result<Vec<Multiaddr>, ConnectionDenied>;
-        }
-    }
-
-    fn handle_established_inbound_connection(
-        &mut self,
-        connection_id: ConnectionId,
-        peer: PeerId,
-        local_addr: &Multiaddr,
-        remote_addr: &Multiaddr,
-    ) -> Result<THandler<Self>, ConnectionDenied> {
-        Ok(ConnectionHandler::select(
-            dummy::ConnectionHandler,
-            self.managed.handle_established_inbound_connection(
-                connection_id,
-                peer,
-                local_addr,
-                remote_addr,
-            )?,
-        ))
-    }
-
-    #[allow(clippy::needless_question_mark)]
-    fn handle_established_outbound_connection(
-        &mut self,
-        connection_id: ConnectionId,
-        peer: PeerId,
-        addr: &Multiaddr,
-        role_override: Endpoint,
-        port_use: PortUse,
-    ) -> Result<THandler<Self>, ConnectionDenied> {
-        Ok(ConnectionHandler::select(
-            dummy::ConnectionHandler,
-            self.managed.handle_established_outbound_connection(
-                connection_id,
-                peer,
-                addr,
-                role_override,
-                port_use,
-            )?,
-        ))
-    }
-
-    fn on_connection_handler_event(
-        &mut self,
-        peer_id: PeerId,
-        connection_id: ConnectionId,
-        event: THandlerOutEvent<Self>,
-    ) {
-        match event {
-            Either::Left(ev) => libp2p::core::util::unreachable(ev),
-            Either::Right(ev) => {
-                self.managed
-                    .on_connection_handler_event(peer_id, connection_id, ev)
-            }
-        }
-    }
-
-    // hook into these methods to drive behavior
-
-    fn on_swarm_event(&mut self, event: FromSwarm) {
-        self.managed.on_swarm_event(event); // let mDNS handle swarm events
-
-        // handle swarm events to update internal state:
-        match event {
-            FromSwarm::ConnectionEstablished(ConnectionEstablished {
-                peer_id,
-                connection_id,
-                endpoint,
-                ..
-            }) => {
-                let remote_address = match endpoint {
-                    ConnectedPoint::Dialer { address, .. } => address,
-                    ConnectedPoint::Listener { send_back_addr, .. } => send_back_addr,
-                };
-
-                if let Some((ip, port)) = remote_address.try_to_tcp_addr() {
-                    // handle connection established event which is filtered correctly
-                    self.on_connection_established(peer_id, connection_id, ip, port)
-                }
-            }
-            FromSwarm::ConnectionClosed(ConnectionClosed {
-                peer_id,
-                connection_id,
-                endpoint,
-                ..
-            }) => {
-                let remote_address = match endpoint {
-                    ConnectedPoint::Dialer { address, .. } => address,
-                    ConnectedPoint::Listener { send_back_addr, .. } => send_back_addr,
-                };
-
-                if let Some((ip, port)) = remote_address.try_to_tcp_addr() {
-                    // handle connection closed event which is filtered correctly
-                    self.on_connection_closed(peer_id, connection_id, ip, port)
-                }
-            }
-
-            // since we are running TCP/IP transport layer, we are assuming that
-            // no address changes can occur, hence encountering one is a fatal error
-            FromSwarm::AddressChange(a) => {
-                unreachable!("unhandlable: address change encountered: {:?}", a)
-            }
-            _ => {}
-        }
-    }
-
-    fn poll(&mut self, cx: &mut Context) -> Poll<ToSwarm<Self::ToSwarm, THandlerInEvent<Self>>> {
-        // delegate to managed behaviors for any behaviors they need to perform
-        match self.managed.poll(cx) {
-            Poll::Ready(ToSwarm::GenerateEvent(e)) => {
-                match e {
-                    // handle discovered and expired events from mDNS
-                    managed::BehaviourEvent::Mdns(e) => match e.clone() {
-                        mdns::Event::Discovered(peers) => {
-                            self.handle_mdns_discovered(peers);
-                        }
-                        mdns::Event::Expired(peers) => {
-                            self.handle_mdns_expired(peers);
-                        }
-                    },
-
-                    // handle ping events => if error then disconnect
-                    managed::BehaviourEvent::Ping(e) => {
-                        if let Err(_) = e.result {
-                            self.close_connection(e.peer, e.connection.clone())
-                        }
-                    }
-                }
-
-                // since we just consumed an event, we should immediately wake just in case
-                // there are more events to come where that came from
-                cx.waker().wake_by_ref();
-            }
-
-            // forward any other mDNS event to the swarm or its connection handler(s)
-            Poll::Ready(e) => {
-                return Poll::Ready(
-                    e.map_out(|_| unreachable!("events returning to swarm already handled"))
-                        .map_in(Either::Right),
-                );
-            }
-
-            Poll::Pending => {}
-        }
-
-        // retry connecting to all mDNS peers periodically (fails safely if already connected)
-        if self.retry_delay.poll(cx).is_ready() {
-            for (p, mas) in self.mdns_discovered.clone() {
-                for ma in mas {
-                    self.dial(p, ma)
-                }
-            }
-            self.retry_delay.reset(RETRY_CONNECT_INTERVAL) // reset timeout
-        }
-
-        // send out any pending events from our own service
-        if let Some(e) = self.pending_events.pop_front(cx) {
-            return Poll::Ready(e.map_in(Either::Left));
-        }
-
-        // wait for pending events
-        Poll::Pending
-    }
-}

rust/networking/src/lib.rs

@@ -3,7 +3,6 @@
 //! this is here as a placeholder documentation
 //!
 //!
-pub mod discovery;
 pub mod swarm;
 
 /// Namespace for all the type/trait aliases used by this crate.

rust/networking/src/swarm.rs

@@ -1,9 +1,11 @@
+use std::collections::HashSet;
 use std::pin::Pin;
 
+use crate::alias;
 use crate::swarm::transport::tcp_transport;
-use crate::{alias, discovery};
 pub use behaviour::{Behaviour, BehaviourEvent};
 use futures_lite::{Stream, StreamExt};
+use libp2p::mdns;
 use libp2p::{PeerId, SwarmBuilder, gossipsub, identity, swarm::SwarmEvent};
 use tokio::sync::{mpsc, oneshot};
 
@@ -68,7 +70,7 @@ impl Swarm {
                     }
                     event = swarm.next() => {
                         let Some(event) = event else { break };
-                        if let Some(item) = filter_swarm_event(event) {
+                        for item in filter_swarm_event(event) {
                             yield item;
                         }
                     }
@@ -115,7 +117,7 @@ fn on_message(swarm: &mut libp2p::Swarm<Behaviour>, message: ToSwarm) {
     }
 }
 
-fn filter_swarm_event(event: SwarmEvent<BehaviourEvent>) -> Option<FromSwarm> {
+fn filter_swarm_event(event: SwarmEvent<BehaviourEvent>) -> Vec<FromSwarm> {
     match event {
         SwarmEvent::Behaviour(BehaviourEvent::Gossipsub(gossipsub::Event::Message {
             message:
@@ -126,19 +128,28 @@ fn filter_swarm_event(event: SwarmEvent<BehaviourEvent>) -> Option<FromSwarm> {
                     ..
                 },
             ..
-        })) => Some(FromSwarm::Message {
+        })) => vec![FromSwarm::Message {
             from: peer_id,
             topic: topic.into_string(),
             data,
-        }),
-        SwarmEvent::Behaviour(BehaviourEvent::Discovery(
-            discovery::Event::ConnectionEstablished { peer_id, .. },
-        )) => Some(FromSwarm::Discovered { peer_id }),
-        SwarmEvent::Behaviour(BehaviourEvent::Discovery(discovery::Event::ConnectionClosed {
-            peer_id,
-            ..
-        })) => Some(FromSwarm::Expired { peer_id }),
-        _ => None,
+        }],
+        SwarmEvent::Behaviour(BehaviourEvent::Discovery(mdns::Event::Discovered(peer_id))) => {
+            peer_id
+                .into_iter()
+                .map(|(pid, _)| pid)
+                .collect::<HashSet<PeerId>>()
+                .into_iter()
+                .map(|peer_id| FromSwarm::Discovered { peer_id })
+                .collect()
+        }
+        SwarmEvent::Behaviour(BehaviourEvent::Discovery(mdns::Event::Expired(peer_id))) => peer_id
+            .into_iter()
+            .map(|(pid, _)| pid)
+            .collect::<HashSet<PeerId>>()
+            .into_iter()
+            .map(|peer_id| FromSwarm::Discovered { peer_id })
+            .collect(),
+        _ => vec![],
     }
 }
 
@@ -233,27 +244,34 @@ mod transport {
 }
 
 mod behaviour {
-    use crate::{alias, discovery};
+    use crate::alias;
     use libp2p::swarm::NetworkBehaviour;
-    use libp2p::{gossipsub, identity};
+    use libp2p::{gossipsub, identity, mdns};
 
     /// Behavior of the Swarm which composes all desired behaviors:
     /// Right now its just [`discovery::Behaviour`] and [`gossipsub::Behaviour`].
     #[derive(NetworkBehaviour)]
     pub struct Behaviour {
-        pub discovery: discovery::Behaviour,
+        pub discovery: mdns::tokio::Behaviour,
         pub gossipsub: gossipsub::Behaviour,
     }
 
     impl Behaviour {
         pub fn new(keypair: &identity::Keypair) -> alias::AnyResult<Self> {
             Ok(Self {
-                discovery: discovery::Behaviour::new(keypair)?,
+                discovery: mdns_behaviour(keypair)?,
                 gossipsub: gossipsub_behaviour(keypair),
             })
         }
     }
 
+    fn mdns_behaviour(keypair: &identity::Keypair) -> alias::AnyResult<mdns::tokio::Behaviour> {
+        Ok(mdns::tokio::Behaviour::new(
+            mdns::Config::default(),
+            keypair.public().to_peer_id(),
+        )?)
+    }
+
     fn gossipsub_behaviour(keypair: &identity::Keypair) -> gossipsub::Behaviour {
         use gossipsub::{ConfigBuilder, MessageAuthenticity, ValidationMode};