Revert "Prevent storing non-contactable ENRs (sigp#246)"

This reverts commit 10cf228.

src/service.rs

@@ -886,13 +886,7 @@ impl Service {
                                 };
                                 self.send_rpc_request(active_request);
                             }
-                            // Only update the routing table if the new ENR is contactable
-                            if self.ip_mode.get_contactable_addr(&enr).is_some() {
-                                self.connection_updated(
-                                    node_id,
-                                    ConnectionStatus::PongReceived(enr),
-                                );
-                            }
+                            self.connection_updated(node_id, ConnectionStatus::PongReceived(enr));
                         }
                     }
                 }
@@ -1194,19 +1188,16 @@ impl Service {
                 return false;
             }
 
+            // If any of the discovered nodes are in the routing table, and there contains an older ENR, update it.
             // If there is an event stream send the Discovered event
             if self.config.report_discovered_peers {
                 self.send_event(Event::Discovered(enr.clone()));
             }
 
-            // Check that peers are compatible to be included into the routing table. They must:
-            // - Pass the table filter
-            // - Be contactable
-            //
-            // Failing this, they are not added, and if there is an older version of them in our
-            // table, we remove them.
-            let key = kbucket::Key::from(enr.node_id());
-            if (self.config.table_filter)(enr) && self.ip_mode.get_contactable_addr(enr).is_some() {
+            // ignore peers that don't pass the table filter
+            if (self.config.table_filter)(enr) {
+                let key = kbucket::Key::from(enr.node_id());
+
                 // If the ENR exists in the routing table and the discovered ENR has a greater
                 // sequence number, perform some filter checks before updating the enr.
 
@@ -1230,22 +1221,7 @@ impl Service {
                     }
                 }
             } else {
-                // Is either non-contactable or didn't pass the table filter. If it exists in the
-                // routing table, remove it.
-                match self.kbuckets.write().entry(&key) {
-                    kbucket::Entry::Present(entry, _) if entry.value().seq() < enr.seq() => {
-                        entry.remove()
-                    }
-                    kbucket::Entry::Pending(mut entry, _) => {
-                        if entry.value().seq() < enr.seq() {
-                            entry.remove()
-                        }
-                    }
-                    _ => {}
-                }
-
-                // Didn't pass the requirements remove the ENR
-                return false;
+                return false; // Didn't pass the table filter remove the peer
             }
 
             // The remaining ENRs are used if this request was part of a query. If we are