service/src/lib: Disable authority discovery querying with reserved only

service/src/lib.rs

@@ -278,7 +278,7 @@ macro_rules! new_full {
 		$dispatch:ty,
 		$informant_prefix:expr $(,)?
 	) => {{
-		use sc_network::Event;
+		use sc_network::{config::NonReservedPeerMode, Event};
 		use sc_client_api::ExecutorProvider;
 		use futures::stream::StreamExt;
 		use sp_core::traits::BareCryptoStorePtr;
@@ -294,6 +294,7 @@ macro_rules! new_full {
 		};
 		let disable_grandpa = $config.disable_grandpa;
 		let name = $config.network.node_name.clone();
+		let non_reserved_peer_mode = $config.network.non_reserved_mode;
 		let authority_discovery_enabled = $authority_discovery_enabled;
 		let slot_duration = $slot_duration;
 
@@ -455,6 +456,10 @@ macro_rules! new_full {
 					_ => unreachable!("Due to outer matches! constraint; qed."),
 				};
 
+				// When a node is only allowed to connect to the configured reserved nodes
+				// (`NonReservedPeerMode::Deny`) there is no benefit in discovering other authorities.
+				let discover_authorities = non_reserved_peer_mode == NonReservedPeerMode::Accept;
+
 				let network = service.network();
 				let network_event_stream = network.event_stream("authority-discovery");
 				let dht_event_stream = network_event_stream.filter_map(|e| async move { match e {
@@ -467,6 +472,7 @@ macro_rules! new_full {
 					sentries,
 					dht_event_stream,
 					authority_discovery_role,
+					discover_authorities,
 					service.prometheus_registry(),
 				);