Print an error if we discover our own network identity (#6047)

* Add an error if we discover our own network identity

* Fix tests

substrate/client/network/src/protocol/generic_proto/behaviour.rs

@@ -109,6 +109,9 @@ use wasm_timer::Instant;
 /// tries to connect, the connection is accepted. A ban only delays dialing attempts.
 ///
 pub struct GenericProto {
+	/// `PeerId` of the local node.
+	local_peer_id: PeerId,
+
 	/// Legacy protocol to open with peers. Never modified.
 	legacy_protocol: RegisteredProtocol,
 
@@ -321,6 +324,7 @@ impl GenericProto {
 	/// The `queue_size_report` is an optional Prometheus metric that can report the size of the
 	/// messages queue. If passed, it must have one label for the protocol name.
 	pub fn new(
+		local_peer_id: PeerId,
 		protocol: impl Into<ProtocolId>,
 		versions: &[u8],
 		peerset: sc_peerset::Peerset,
@@ -329,6 +333,7 @@ impl GenericProto {
 		let legacy_protocol = RegisteredProtocol::new(protocol, versions);
 
 		GenericProto {
+			local_peer_id,
 			legacy_protocol,
 			notif_protocols: Vec::new(),
 			peerset,
@@ -507,9 +512,18 @@ impl GenericProto {
 	///
 	/// Can be called multiple times with the same `PeerId`s.
 	pub fn add_discovered_nodes(&mut self, peer_ids: impl Iterator<Item = PeerId>) {
-		self.peerset.discovered(peer_ids.map(|peer_id| {
+		let local_peer_id = &self.local_peer_id;
+		self.peerset.discovered(peer_ids.filter_map(|peer_id| {
+			if peer_id == *local_peer_id {
+				error!(
+					target: "sub-libp2p",
+					"Discovered our own identity. This is a minor inconsequential bug."
+				);
+				return None;
+			}
+
 			debug!(target: "sub-libp2p", "PSM <= Discovered({:?})", peer_id);
-			peer_id
+			Some(peer_id)
 		}));
 	}
 

substrate/client/network/src/protocol/generic_proto/tests.rs

@@ -42,6 +42,7 @@ fn build_nodes() -> (Swarm<CustomProtoWithAddr>, Swarm<CustomProtoWithAddr>) {
 
 	for index in 0 .. 2 {
 		let keypair = keypairs[index].clone();
+		let local_peer_id = keypair.public().into_peer_id();
 		let transport = libp2p::core::transport::MemoryTransport
 			.and_then(move |out, endpoint| {
 				let secio = libp2p::secio::SecioConfig::new(keypair);
@@ -82,7 +83,7 @@ fn build_nodes() -> (Swarm<CustomProtoWithAddr>, Swarm<CustomProtoWithAddr>) {
 		});
 
 		let behaviour = CustomProtoWithAddr {
-			inner: GenericProto::new(&b"test"[..], &[1], peerset, None),
+			inner: GenericProto::new(local_peer_id, &b"test"[..], &[1], peerset, None),
 			addrs: addrs
 				.iter()
 				.enumerate()