1 files changed, 33 insertions, 6 deletions

diff --git a/src/transport/libp2p.rs b/src/transport/libp2p.rs
index 76d07ff..237fd8a 100644
--- a/src/transport/libp2p.rs
+++ b/src/transport/libp2p.rs
@@ -201,8 +201,8 @@ struct Book {
     failed_relays: HashMap<PeerId, tokio::time::Instant>,
     /// Relays that granted us a slot we hold.
     slots: std::collections::HashSet<PeerId>,
-    /// Open connections: to whom, and whether through a relay.
-    connections: HashMap<ConnectionId, (PeerId, bool)>,
+    /// Open connections: to whom, whether through a relay, and the remote address.
+    connections: HashMap<ConnectionId, (PeerId, bool, Multiaddr)>,
     /// What AutoNAT says, and the address it confirmed while public.
     reachability: Reachability,
     public_address: Option<Multiaddr>,
@@ -245,7 +245,7 @@ impl Book {
     /// How we are connected to `peer`: directly if any connection is direct.
     fn connection(&self, peer: &PeerId) -> Option<Connection> {
         let mut found = None;
-        for (connected, relayed) in self.connections.values() {
+        for (connected, relayed, _) in self.connections.values() {
             if connected == peer {
                 if !relayed {
                     return Some(Connection::Direct);
@@ -256,9 +256,23 @@ impl Book {
         found
     }
 
+    /// The remote address of a connection to `peer`: a direct one if there is one.
+    fn location(&self, peer: &PeerId) -> Option<&Multiaddr> {
+        let mut found = None;
+        for (connected, relayed, address) in self.connections.values() {
+            if connected == peer {
+                if !relayed {
+                    return Some(address);
+                }
+                found = Some(address);
+            }
+        }
+        found
+    }
+
     fn stats(&self) -> Libp2pStats {
         let mut connections = Connections::default();
-        for (_, relayed) in self.connections.values() {
+        for (_, relayed, _) in self.connections.values() {
             if *relayed {
                 connections.relayed += 1;
             } else {
@@ -966,7 +980,10 @@ async fn run(
                         let mut book = lock(&book);
                         book.touch(peer_id);
                         let relayed = endpoint.is_relayed();
-                        book.connections.insert(connection_id, (peer_id, relayed));
+                        book.connections.insert(
+                            connection_id,
+                            (peer_id, relayed, endpoint.get_remote_address().clone()),
+                        );
                         debug!(
                             peer = %peer_id,
                             connection = %connection_id,
@@ -1297,6 +1314,11 @@ impl Transport for Libp2pTransport {
         lock(&self.book).connection(&peer)
     }
 
+    fn location(&self, target: &str) -> Option<String> {
+        let peer = PeerId::from_str(target).ok()?;
+        lock(&self.book).location(&peer).map(Multiaddr::to_string)
+    }
+
     fn stats(&self) -> TransportStats {
         TransportStats {
             libp2p: Some(lock(&self.book).stats()),
@@ -1826,8 +1848,9 @@ mod tests {
         let mut id = 0;
         let mut connect = |book: &mut Book, peer: PeerId, relayed: bool| {
             id += 1;
+            let address: Multiaddr = format!("/ip4/10.0.0.{id}/tcp/1").parse().unwrap();
             book.connections
-                .insert(ConnectionId::new_unchecked(id), (peer, relayed));
+                .insert(ConnectionId::new_unchecked(id), (peer, relayed, address));
         };
         connect(&mut book, relayed_only, true);
         connect(&mut book, both, true);
@@ -1835,6 +1858,10 @@ mod tests {
         assert_eq!(book.connection(&relayed_only), Some(Connection::Relayed));
         assert_eq!(book.connection(&both), Some(Connection::Direct));
         assert_eq!(book.connection(&peer()), None);
+        assert_eq!(
+            book.location(&both).map(|address| address.to_string()),
+            Some("/ip4/10.0.0.3/tcp/1".to_owned())
+        );
         let connections = book.stats().connections;
         assert_eq!((connections.direct, connections.relayed), (1, 2));
     }