[NOD-1150] Add in netadapter function to disconnect router (#797)

* [NOD-1150] Add in netadapter function to disconnect router

* [NOD-1150] Fix comment

netadapter/netadapter.go

@@ -101,6 +101,9 @@ func (na *NetAdapter) newOnConnectedHandler() server.OnConnectedHandler {
 		router.SetOnRouteCapacityReachedHandler(func() {
 			err := connection.Disconnect()
 			if err != nil {
+				if !errors.Is(err, server.ErrNetwork) {
+					panic(err)
+				}
 				log.Warnf("Failed to disconnect from %s", connection)
 			}
 		})
@@ -222,3 +225,16 @@ func (na *NetAdapter) GetBestLocalAddress() (*wire.NetAddress, error) {
 	}
 	return nil, errors.New("no address was found")
 }
+
+// DisconnectAssociatedConnection disconnects from the connection associated with the given router.
+func (na *NetAdapter) DisconnectAssociatedConnection(router *routerpkg.Router) error {
+	connection := na.routersToConnections[router]
+	err := connection.Disconnect()
+	if err != nil {
+		if !errors.Is(err, server.ErrNetwork) {
+			return err
+		}
+		log.Warnf("Error disconnecting from %s: %s", connection, err)
+	}
+	return nil
+}

netadapter/server/server.go

@@ -3,6 +3,7 @@ package server
 import (
 	"fmt"
 	"github.com/kaspanet/kaspad/netadapter/router"
+	"github.com/pkg/errors"
 	"net"
 )
 
@@ -35,3 +36,7 @@ type Connection interface {
 	SetOnDisconnectedHandler(onDisconnectedHandler OnDisconnectedHandler)
 	Address() net.Addr
 }
+
+// ErrNetwork is an error related to the internals of the connection, and not an error that
+// came from outside (e.g. from OnDisconnectedHandler).
+var ErrNetwork = errors.New("network error")

protocol/protocol.go

@@ -60,12 +60,18 @@ func newRouterInitializer(netAdapter *netadapter.NetAdapter,
 						// TODO(libp2p) Ban peer
 						panic("unimplemented")
 					}
-					// TODO(libp2p) Disconnect from peer
-					panic("unimplemented")
+					err = netAdapter.DisconnectAssociatedConnection(router)
+					if err != nil {
+						panic(err)
+					}
+					return
 				}
 				if errors.Is(err, routerpkg.ErrTimeout) {
-					// TODO(libp2p) Disconnect peer
-					panic("unimplemented")
+					err = netAdapter.DisconnectAssociatedConnection(router)
+					if err != nil {
+						panic(err)
+					}
+					return
 				}
 				panic(err)
 			}