Check for session expiration on peer registration

sync/src/chain.rs

@@ -356,6 +356,10 @@ impl ChainSync {
 		};
 
 		trace!(target: "sync", "New peer {} (protocol: {}, network: {:?}, difficulty: {:?}, latest:{}, genesis:{})", peer_id, peer.protocol_version, peer.network_id, peer.difficulty, peer.latest_hash, peer.genesis);
+		if io.is_expired() {
+			info!("Status packet from expired session {}:{}", peer_id, io.peer_info(peer_id));
+			return Ok(());
+		}
 
 		if self.peers.contains_key(&peer_id) {
 			warn!("Unexpected status packet from {}:{}", peer_id, io.peer_info(peer_id));

sync/src/io.rs

@@ -41,6 +41,8 @@ pub trait SyncIo {
 	fn is_chain_queue_empty(&self) -> bool {
 		self.chain().queue_info().is_empty()
 	}
+	/// Check if the session is expired
+	fn is_expired(&self) -> bool;
 }
 
 /// Wraps `NetworkContext` and the blockchain client
@@ -83,6 +85,10 @@ impl<'s, 'h> SyncIo for NetSyncIo<'s, 'h> {
 	fn peer_info(&self, peer_id: PeerId) -> String {
 		self.network.peer_info(peer_id)
 	}
+
+	fn is_expired(&self) -> bool {
+		self.network.is_expired()
+	}
 }
 
 

sync/src/tests/chain.rs

@@ -192,3 +192,13 @@ fn restart_on_broken_chain() {
 
 	assert_eq!(net.peer(0).chain.chain_info().best_block_number, 5);
 }
+
+#[test]
+fn high_td_attach() {
+	let mut net = TestNet::new(2);
+	net.peer_mut(1).chain.add_blocks(10, EachBlockWith::Uncle);
+	net.peer_mut(1).chain.corrupt_block_parent(6);
+	net.sync_steps(20);
+
+	assert_eq!(net.peer(0).chain.chain_info().best_block_number, 5);
+}