feat(rendezous): refresh registration on change to external addresses

Resolves #4627.

Pull-Request: #4629.

Cargo.toml

@@ -97,7 +97,7 @@ libp2p-plaintext = { version = "0.40.1", path = "transports/plaintext" }
 libp2p-pnet = { version = "0.23.0", path = "transports/pnet" }
 libp2p-quic = { version = "0.9.3", path = "transports/quic" }
 libp2p-relay = { version = "0.16.1", path = "protocols/relay" }
-libp2p-rendezvous = { version = "0.13.0", path = "protocols/rendezvous" }
+libp2p-rendezvous = { version = "0.13.1", path = "protocols/rendezvous" }
 libp2p-upnp = { version = "0.1.1", path = "protocols/upnp" }
 libp2p-request-response = { version = "0.25.1", path = "protocols/request-response" }
 libp2p-server = { version = "0.12.3", path = "misc/server" }

protocols/rendezvous/CHANGELOG.md

@@ -1,3 +1,9 @@
+## 0.13.1 - unreleased
+- Refresh registration upon a change in external addresses.
+  See [PR 4629].
+
+[PR 4629]: https://github.com/libp2p/rust-libp2p/pull/4629
+
 ## 0.13.0 
 
 - Changed the signature of the function `client::Behavior::register()`,

protocols/rendezvous/Cargo.toml

@@ -3,7 +3,7 @@ name = "libp2p-rendezvous"
 edition = "2021"
 rust-version = { workspace = true }
 description = "Rendezvous protocol for libp2p"
-version = "0.13.0"
+version = "0.13.1"
 authors = ["The COMIT guys <hello@comit.network>"]
 license = "MIT"
 repository = "https://github.com/libp2p/rust-libp2p"

protocols/rendezvous/src/client.rs

@@ -49,6 +49,8 @@ pub struct Behaviour {
     /// Storing these internally allows us to assist the [`libp2p_swarm::Swarm`] in dialing by returning addresses from [`NetworkBehaviour::handle_pending_outbound_connection`].
     discovered_peers: HashMap<(PeerId, Namespace), Vec<Multiaddr>>,
 
+    registered_namespaces: HashMap<(PeerId, Namespace), Ttl>,
+
     /// Tracks the expiry of registrations that we have discovered and stored in `discovered_peers` otherwise we have a memory leak.
     expiring_registrations: FuturesUnordered<BoxFuture<'static, (PeerId, Namespace)>>,
 
@@ -68,6 +70,7 @@ impl Behaviour {
             waiting_for_register: Default::default(),
             waiting_for_discovery: Default::default(),
             discovered_peers: Default::default(),
+            registered_namespaces: Default::default(),
             expiring_registrations: FuturesUnordered::from_iter(vec![
                 futures::future::pending().boxed()
             ]),
@@ -103,6 +106,9 @@ impl Behaviour {
 
     /// Unregister ourselves from the given namespace with the given rendezvous peer.
     pub fn unregister(&mut self, namespace: Namespace, rendezvous_node: PeerId) {
+        self.registered_namespaces
+            .retain(|(rz_node, ns), _| rz_node.ne(&rendezvous_node) && ns.ne(&namespace));
+
         self.inner
             .send_request(&rendezvous_node, Unregister(namespace));
     }
@@ -218,9 +224,18 @@ impl NetworkBehaviour for Behaviour {
     }
 
     fn on_swarm_event(&mut self, event: FromSwarm<Self::ConnectionHandler>) {
-        self.external_addresses.on_swarm_event(&event);
+        let changed = self.external_addresses.on_swarm_event(&event);
 
         self.inner.on_swarm_event(event);
+
+        if changed && self.external_addresses.iter().count() > 0 {
+            let registered = self.registered_namespaces.clone();
+            for ((rz_node, ns), ttl) in registered {
+                if let Err(e) = self.register(ns, rz_node, Some(ttl)) {
+                    log::warn!("refreshing registration failed: {e}")
+                }
+            }
+        }
     }
 
     fn poll(
@@ -348,6 +363,9 @@ impl Behaviour {
                 if let Some((rendezvous_node, namespace)) =
                     self.waiting_for_register.remove(request_id)
                 {
+                    self.registered_namespaces
+                        .insert((rendezvous_node, namespace.clone()), ttl);
+
                     return Some(Event::Registered {
                         rendezvous_node,
                         ttl,

protocols/rendezvous/tests/rendezvous.rs

@@ -20,6 +20,8 @@
 
 use futures::stream::FuturesUnordered;
 use futures::StreamExt;
+use libp2p_core::multiaddr::Protocol;
+use libp2p_core::Multiaddr;
 use libp2p_identity as identity;
 use libp2p_rendezvous as rendezvous;
 use libp2p_rendezvous::client::RegisterError;
@@ -162,6 +164,57 @@ async fn given_successful_registration_then_refresh_ttl() {
     }
 }
 
+#[tokio::test]
+async fn given_successful_registration_then_refresh_external_addrs() {
+    let _ = env_logger::try_init();
+    let namespace = rendezvous::Namespace::from_static("some-namespace");
+    let ([mut alice], mut robert) =
+        new_server_with_connected_clients(rendezvous::server::Config::default()).await;
+
+    let roberts_peer_id = *robert.local_peer_id();
+
+    alice
+        .behaviour_mut()
+        .register(namespace.clone(), roberts_peer_id, None)
+        .unwrap();
+
+    match libp2p_swarm_test::drive(&mut alice, &mut robert).await {
+        (
+            [rendezvous::client::Event::Registered { .. }],
+            [rendezvous::server::Event::PeerRegistered { .. }],
+        ) => {}
+        events => panic!("Unexpected events: {events:?}"),
+    }
+
+    let external_addr = Multiaddr::empty().with(Protocol::Memory(0));
+
+    alice.add_external_address(external_addr.clone());
+
+    match libp2p_swarm_test::drive(&mut alice, &mut robert).await {
+        (
+            [rendezvous::client::Event::Registered { .. }],
+            [rendezvous::server::Event::PeerRegistered { registration, .. }],
+        ) => {
+            let record = registration.record;
+            assert!(record.addresses().contains(&external_addr));
+        }
+        events => panic!("Unexpected events: {events:?}"),
+    }
+
+    alice.remove_external_address(&external_addr);
+
+    match libp2p_swarm_test::drive(&mut alice, &mut robert).await {
+        (
+            [rendezvous::client::Event::Registered { .. }],
+            [rendezvous::server::Event::PeerRegistered { registration, .. }],
+        ) => {
+            let record = registration.record;
+            assert!(!record.addresses().contains(&external_addr));
+        }
+        events => panic!("Unexpected events: {events:?}"),
+    }
+}
+
 #[tokio::test]
 async fn given_invalid_ttl_then_unsuccessful_registration() {
     let _ = env_logger::try_init();