Always print why we disconnect explicitly

...and drop the old, confusing, "protocol error" message when we
get a duplicate connection from a peer.

This should slightly further disambiguate disconnection reasons,
which are a key debugging tool for assigning blame.

diff --git a/lightning/src/ln/peer_handler.rs b/lightning/src/ln/peer_handler.rs
index 51695bba09afc01e62afac9c69c259eba591677c..80c9c78101e7eb33bdbf3abded9524f8d34d1b88 100644 (file)
--- a/lightning/src/ln/peer_handler.rs
+++ b/lightning/src/ln/peer_handler.rs
@@ -1333,8 +1333,7 @@ impl<Descriptor: SocketDescriptor, CM: Deref, RM: Deref, OM: Deref, L: Deref, CM
                match self.do_read_event(peer_descriptor, data) {
                        Ok(res) => Ok(res),
                        Err(e) => {
-                               log_trace!(self.logger, "Disconnecting peer due to a protocol error (usually a duplicate connection).");
-                               self.disconnect_event_internal(peer_descriptor);
+                               self.disconnect_event_internal(peer_descriptor, "of a protocol error");
                                Err(e)
                        }
                }
@@ -2435,7 +2434,7 @@ impl<Descriptor: SocketDescriptor, CM: Deref, RM: Deref, OM: Deref, L: Deref, CM
 
        /// Indicates that the given socket descriptor's connection is now closed.
        pub fn socket_disconnected(&self, descriptor: &Descriptor) {
-               self.disconnect_event_internal(descriptor);
+               self.disconnect_event_internal(descriptor, "the socket was disconnected");
        }
 
        fn do_disconnect(&self, mut descriptor: Descriptor, peer: &Peer, reason: &'static str) {
@@ -2455,7 +2454,7 @@ impl<Descriptor: SocketDescriptor, CM: Deref, RM: Deref, OM: Deref, L: Deref, CM
                descriptor.disconnect_socket();
        }
 
-       fn disconnect_event_internal(&self, descriptor: &Descriptor) {
+       fn disconnect_event_internal(&self, descriptor: &Descriptor, reason: &'static str) {
                let mut peers = self.peers.write().unwrap();
                let peer_option = peers.remove(descriptor);
                match peer_option {
@@ -2467,7 +2466,8 @@ impl<Descriptor: SocketDescriptor, CM: Deref, RM: Deref, OM: Deref, L: Deref, CM
                        Some(peer_lock) => {
                                let peer = peer_lock.lock().unwrap();
                                if let Some((node_id, _)) = peer.their_node_id {
-                                       log_trace!(WithContext::from(&self.logger, Some(node_id), None, None), "Handling disconnection of peer {}", log_pubkey!(node_id));
+                                       let logger = WithContext::from(&self.logger, Some(node_id), None, None);
+                                       log_trace!(logger, "Handling disconnection of peer {} because {}", log_pubkey!(node_id), reason);
                                        let removed = self.node_id_to_descriptor.lock().unwrap().remove(&node_id);
                                        debug_assert!(removed.is_some(), "descriptor maps should be consistent");
                                        if !peer.handshake_complete() { return; }