split out node callback between tinygo and go to avoid heap allocs

internet/definitions_tinygo.go

@@ -0,0 +1,29 @@
+//go:build tinygo
+
+package internet
+
+func makecbnode(s StackNode) cbnode {
+	return cbnode{
+		demux:       s.Demux,
+		encapsulate: s.Encapsulate,
+	}
+}
+
+type cbnode struct {
+	// Do not access outside of handlers/node logic.
+	demux func([]byte, int) error
+	// Do not access outside of handlers/node logic.
+	encapsulate func([]byte, int, int) (int, error)
+}
+
+func (s *cbnode) Encapsulate(carrierData []byte, offsetToIP, offsetToFrame int) (int, error) {
+	return s.encapsulate(carrierData, offsetToIP, offsetToFrame)
+}
+
+func (s *cbnode) Demux(carrierData []byte, frameOffset int) error {
+	return s.demux(carrierData, frameOffset)
+}
+
+func (s cbnode) IsZeroed() bool {
+	return s.demux == nil || s.encapsulate == nil
+}