Use a Kademlia instance per ProtocolId.

Cargo.toml

@@ -166,3 +166,6 @@ members = [
 [profile.release]
 # Substrate runtime requires unwinding.
 panic = "unwind"
+
+[patch.crates-io]
+libp2p = { git = "https://github.com/libp2p/rust-libp2p" }

client/network/src/behaviour.rs

@@ -15,6 +15,7 @@
 // along with Substrate.  If not, see <http://www.gnu.org/licenses/>.
 
 use crate::{
+	config::ProtocolId,
 	debug_info, discovery::DiscoveryBehaviour, discovery::DiscoveryOut, DiscoveryNetBehaviour,
 	Event, protocol::event::DhtEvent, ExHashT,
 };
@@ -86,6 +87,11 @@ impl<B: BlockT, H: ExHashT> Behaviour<B, H> {
 		}
 	}
 
+	/// Enable discovery for the given protocol.
+	pub fn add_discovery(&mut self, p: ProtocolId) {
+		self.discovery.add_discovery(p)
+	}
+
 	/// Returns the list of nodes that we know exist in the network.
 	pub fn known_peers(&mut self) -> impl Iterator<Item = &PeerId> {
 		self.discovery.known_peers()