feat(relay): emit external address on reservation

Resolves #4618.

Pull-Request: #4809.

Cargo.toml

@@ -94,7 +94,7 @@ libp2p-ping = { version = "0.44.0", path = "protocols/ping" }
 libp2p-plaintext = { version = "0.41.0", path = "transports/plaintext" }
 libp2p-pnet = { version = "0.24.0", path = "transports/pnet" }
 libp2p-quic = { version = "0.10.1", path = "transports/quic" }
-libp2p-relay = { version = "0.17.0", path = "protocols/relay" }
+libp2p-relay = { version = "0.17.1", path = "protocols/relay" }
 libp2p-rendezvous = { version = "0.14.0", path = "protocols/rendezvous" }
 libp2p-request-response = { version = "0.26.0", path = "protocols/request-response" }
 libp2p-server = { version = "0.12.4", path = "misc/server" }

protocols/dcutr/tests/lib.rs

@@ -200,6 +200,9 @@ async fn wait_for_reservation(
             }
             SwarmEvent::Behaviour(ClientEvent::Identify(_)) => {}
             SwarmEvent::NewExternalAddrCandidate { .. } => {}
+            SwarmEvent::ExternalAddrConfirmed { address } if !is_renewal => {
+                assert_eq!(address, client_addr);
+            }
             e => panic!("{e:?}"),
         }
     }

protocols/relay/CHANGELOG.md

@@ -1,5 +1,9 @@
-## 0.17.0
 
+## 0.17.1 - unreleased
+- Automatically register relayed addresses as external addresses.
+  See [PR 4809](https://github.com/libp2p/rust-lib2pp/pulls/4809).
+
+## 0.17.0
 - Don't close connections on protocol failures within the relay-server.
   To achieve this, error handling was restructured:
   - `libp2p::relay::outbound::stop::FatalUpgradeError` has been removed.

protocols/relay/Cargo.toml

@@ -3,7 +3,7 @@ name = "libp2p-relay"
 edition = "2021"
 rust-version = { workspace = true }
 description = "Communications relaying for libp2p"
-version = "0.17.0"
+version = "0.17.1"
 authors = ["Parity Technologies <[email protected]>", "Max Inden <[email protected]>"]
 license = "MIT"
 repository = "https://github.com/libp2p/rust-libp2p"

protocols/relay/src/priv_client.rs

@@ -33,6 +33,7 @@ use futures::future::{BoxFuture, FutureExt};
 use futures::io::{AsyncRead, AsyncWrite};
 use futures::ready;
 use futures::stream::StreamExt;
+use libp2p_core::multiaddr::Protocol;
 use libp2p_core::{Endpoint, Multiaddr};
 use libp2p_identity::PeerId;
 use libp2p_swarm::behaviour::{ConnectionClosed, ConnectionEstablished, FromSwarm};
@@ -69,6 +70,12 @@ pub enum Event {
     },
 }
 
+#[derive(Debug, Copy, Clone, PartialEq, Eq)]
+enum ReservationStatus {
+    Pending,
+    Confirmed,
+}
+
 /// [`NetworkBehaviour`] implementation of the relay client
 /// functionality of the circuit relay v2 protocol.
 pub struct Behaviour {
@@ -79,6 +86,11 @@ pub struct Behaviour {
     /// connection.
     directly_connected_peers: HashMap<PeerId, Vec<ConnectionId>>,
 
+    /// Stores the address of a pending or confirmed reservation.
+    ///
+    /// This is indexed by the [`ConnectionId`] to a relay server and the address is the `/p2p-circuit` address we reserved on it.
+    reservation_addresses: HashMap<ConnectionId, (Multiaddr, ReservationStatus)>,
+
     /// Queue of actions to return when polled.
     queued_actions: VecDeque<ToSwarm<Event, Either<handler::In, Void>>>,
 
@@ -92,6 +104,7 @@ pub fn new(local_peer_id: PeerId) -> (Transport, Behaviour) {
         local_peer_id,
         from_transport,
         directly_connected_peers: Default::default(),
+        reservation_addresses: Default::default(),
         queued_actions: Default::default(),
         pending_handler_commands: Default::default(),
     };
@@ -126,6 +139,12 @@ impl Behaviour {
                     unreachable!("`on_connection_closed` for unconnected peer.")
                 }
             };
+            if let Some((addr, ReservationStatus::Confirmed)) =
+                self.reservation_addresses.remove(&connection_id)
+            {
+                self.queued_actions
+                    .push_back(ToSwarm::ExternalAddrExpired(addr));
+            }
         }
     }
 }
@@ -200,6 +219,7 @@ impl NetworkBehaviour for Behaviour {
                 self.on_connection_closed(connection_closed)
             }
             FromSwarm::DialFailure(DialFailure { connection_id, .. }) => {
+                self.reservation_addresses.remove(&connection_id);
                 self.pending_handler_commands.remove(&connection_id);
             }
             _ => {}
@@ -209,7 +229,7 @@ impl NetworkBehaviour for Behaviour {
     fn on_connection_handler_event(
         &mut self,
         event_source: PeerId,
-        _connection: ConnectionId,
+        connection: ConnectionId,
         handler_event: THandlerOutEvent<Self>,
     ) {
         let handler_event = match handler_event {
@@ -219,6 +239,17 @@ impl NetworkBehaviour for Behaviour {
 
         let event = match handler_event {
             handler::Event::ReservationReqAccepted { renewal, limit } => {
+                let (addr, status) = self
+                    .reservation_addresses
+                    .get_mut(&connection)
+                    .expect("Relay connection exist");
+
+                if !renewal && *status == ReservationStatus::Pending {
+                    *status = ReservationStatus::Confirmed;
+                    self.queued_actions
+                        .push_back(ToSwarm::ExternalAddrConfirmed(addr.clone()));
+                }
+
                 Event::ReservationReqAccepted {
                     relay_peer_id: event_source,
                     renewal,
@@ -236,7 +267,7 @@ impl NetworkBehaviour for Behaviour {
             }
         };
 
-        self.queued_actions.push_back(ToSwarm::GenerateEvent(event))
+        self.queued_actions.push_back(ToSwarm::GenerateEvent(event));
     }
 
     #[tracing::instrument(level = "trace", name = "NetworkBehaviour::poll", skip(self, cx))]
@@ -259,18 +290,42 @@ impl NetworkBehaviour for Behaviour {
                     .get(&relay_peer_id)
                     .and_then(|cs| cs.first())
                 {
-                    Some(connection_id) => ToSwarm::NotifyHandler {
-                        peer_id: relay_peer_id,
-                        handler: NotifyHandler::One(*connection_id),
-                        event: Either::Left(handler::In::Reserve { to_listener }),
-                    },
+                    Some(connection_id) => {
+                        self.reservation_addresses.insert(
+                            *connection_id,
+                            (
+                                relay_addr
+                                    .with(Protocol::P2p(relay_peer_id))
+                                    .with(Protocol::P2pCircuit)
+                                    .with(Protocol::P2p(self.local_peer_id)),
+                                ReservationStatus::Pending,
+                            ),
+                        );
+
+                        ToSwarm::NotifyHandler {
+                            peer_id: relay_peer_id,
+                            handler: NotifyHandler::One(*connection_id),
+                            event: Either::Left(handler::In::Reserve { to_listener }),
+                        }
+                    }
                     None => {
                         let opts = DialOpts::peer_id(relay_peer_id)
-                            .addresses(vec![relay_addr])
+                            .addresses(vec![relay_addr.clone()])
                             .extend_addresses_through_behaviour()
                             .build();
                         let relayed_connection_id = opts.connection_id();
 
+                        self.reservation_addresses.insert(
+                            relayed_connection_id,
+                            (
+                                relay_addr
+                                    .with(Protocol::P2p(relay_peer_id))
+                                    .with(Protocol::P2pCircuit)
+                                    .with(Protocol::P2p(self.local_peer_id)),
+                                ReservationStatus::Pending,
+                            ),
+                        );
+
                         self.pending_handler_commands
                             .insert(relayed_connection_id, handler::In::Reserve { to_listener });
                         ToSwarm::Dial { opts }

protocols/relay/tests/lib.rs

@@ -119,7 +119,7 @@ fn new_reservation_to_same_relay_replaces_old() {
     ));
 
     // Trigger new reservation.
-    let new_listener = client.listen_on(client_addr).unwrap();
+    let new_listener = client.listen_on(client_addr.clone()).unwrap();
 
     // Wait for
     // - listener of old reservation to close
@@ -169,6 +169,12 @@ fn new_reservation_to_same_relay_replaces_old() {
                         break;
                     }
                 }
+                SwarmEvent::ExternalAddrConfirmed { address } => {
+                    assert_eq!(
+                        address,
+                        client_addr.clone().with(Protocol::P2p(client_peer_id))
+                    );
+                }
                 SwarmEvent::Behaviour(ClientEvent::Ping(_)) => {}
                 e => panic!("{e:?}"),
             }
@@ -521,6 +527,9 @@ async fn wait_for_reservation(
 
     loop {
         match client.select_next_some().await {
+            SwarmEvent::ExternalAddrConfirmed { address } if !is_renewal => {
+                assert_eq!(address, client_addr);
+            }
             SwarmEvent::Behaviour(ClientEvent::Relay(
                 relay::client::Event::ReservationReqAccepted {
                     relay_peer_id: peer_id,