Report local force-closing connections to Prometheus (#5575)

* Report local force-closing connections to Prometheus

* Also report ping timeouts separately

* Address concerns of #5571

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

@@ -21,6 +21,7 @@
 //! network, then performs the Substrate protocol handling on top.
 
 pub use self::behaviour::{GenericProto, GenericProtoOut};
+pub use self::handler::LegacyConnectionKillError;
 
 mod behaviour;
 mod handler;

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

@@ -1193,10 +1193,10 @@ impl NetworkBehaviour for GenericProto {
 			}
 
 			NotifsHandlerOut::ProtocolError { error, .. } => {
-				warn!(target: "sub-libp2p",
+				debug!(target: "sub-libp2p",
 					"Handler({:?}) => Severe protocol error: {:?}",
 					source, error);
-				// A severe protocol error happens when we detect a "bad" peer, such as a per on
+				// A severe protocol error happens when we detect a "bad" peer, such as a peer on
 				// a different chain, or a peer that doesn't speak the same protocol(s). We
 				// decrease the peer's reputation, hence lowering the chances we try this peer
 				// again in the short term.

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

@@ -15,6 +15,7 @@
 // along with Substrate.  If not, see <http://www.gnu.org/licenses/>.
 
 pub use self::group::{NotifsHandlerProto, NotifsHandler, NotifsHandlerIn, NotifsHandlerOut};
+pub use self::legacy::ConnectionKillError as LegacyConnectionKillError;
 
 mod group;
 mod legacy;