drop ECN support for this release

main.go

@@ -260,7 +260,6 @@ func Main(c *config.C, configTest bool, buildVersion string, l *slog.Logger, dev
 		ifce.reloadDisconnectInvalid(c)
 		ifce.reloadSendRecvError(c)
 		ifce.reloadAcceptRecvError(c)
-		ifce.reloadEcn(c)
 
 		handshakeManager.f = ifce
 		go handshakeManager.Run(ctx)

overlay/batch/multi_coalesce.go

@@ -125,7 +125,7 @@ func (m *MultiCoalescer) Commit(pkt []byte) error {
 		if m.udp != nil {
 			info, ok := parseUDP(pkt)
 			if !ok {
-				m.udp.addPassthrough(pkt) //we could also m.pt.Commit() here I guess?
+				m.udp.addPassthrough(pkt)
 				return nil
 			}
 			return m.udp.commitParsed(pkt, info)

overlay/tun_linux.go

@@ -36,7 +36,6 @@ type tun struct {
 	ioctlFd      uintptr
 	vnetHdr      bool
 	offloadFlags uint
-	routeFeatureECN bool
 
 	Routes                    atomic.Pointer[[]Route]
 	routeTree                 atomic.Pointer[bart.Table[routing.Gateways]]
@@ -223,7 +222,6 @@ func newTunGeneric(c *config.C, l *slog.Logger, fd int, vnetHdr bool, offloadFla
 		TXQueueLen:                c.GetInt("tun.tx_queue", 500),
 		useSystemRoutes:           c.GetBool("tun.use_system_route_table", false),
 		useSystemRoutesBufferSize: c.GetInt("tun.use_system_route_table_buffer_size", 0),
-		routeFeatureECN:           c.GetBool("tunnels.ecn", true), //todo!!!
 		routesFromSystem:          map[netip.Prefix]routing.Gateways{},
 		l:                         l,
 	}
@@ -534,9 +532,6 @@ func (t *tun) setDefaultRoute(cidr netip.Prefix) error {
 	if cidr.Addr().Is6() {
 		nr.Priority = 256
 	}
-	if t.routeFeatureECN {
-		nr.Features |= unix.RTAX_FEATURE_ECN
-	}
 	err := netlink.RouteReplace(&nr)
 	if err != nil {
 		t.l.Warn("Failed to set default route MTU, retrying", "error", err, "cidr", cidr)
@@ -586,9 +581,6 @@ func (t *tun) addRoutes(logErrors bool) error {
 		if r.Metric > 0 {
 			nr.Priority = r.Metric
 		}
-		if t.routeFeatureECN {
-			nr.Features |= unix.RTAX_FEATURE_ECN
-		}
 
 		err := netlink.RouteReplace(&nr)
 		if err != nil {