slight file reordering

internet/stack-ports.go

@@ -0,0 +1,81 @@
+package internet
+
+import (
+	"encoding/binary"
+	"io"
+)
+
+type StackPorts struct {
+	connID     uint64
+	protocol   uint64
+	handlers   []node
+	dstPortOff int
+}
+
+func (ps *StackPorts) Reset(protocol uint64, dstPortOffset int) {
+	*ps = StackPorts{
+		connID:     ps.connID + 1,
+		handlers:   ps.handlers[:0],
+		dstPortOff: dstPortOffset,
+		protocol:   protocol,
+	}
+}
+func (ps *StackPorts) LocalPort() uint16 { return 0 }
+
+func (ps *StackPorts) Protocol() uint64 { return ps.protocol }
+
+func (ps *StackPorts) ConnectionID() *uint64 { return &ps.connID }
+
+func (ps *StackPorts) Encapsulate(b []byte, offset int) (n int, err error) {
+	if ps.dstPortOff+offset+2 > len(b) {
+		return 0, io.ErrShortBuffer
+	}
+	var i int
+	for i = 0; i < len(ps.handlers); i++ {
+		n, err = ps.handlers[i].encapsulate(b, offset)
+		if err != nil || n > 0 {
+			break
+		}
+	}
+	ps.handleResult(i, n, err)
+	return n, err
+}
+
+func (ps *StackPorts) Demux(b []byte, offset int) (err error) {
+	if ps.dstPortOff+offset+2 > len(b) {
+		return io.ErrShortBuffer
+	}
+	port := binary.BigEndian.Uint16(b[ps.dstPortOff+offset:])
+	var i int
+	for i = 0; i < len(ps.handlers); i++ {
+		if port != ps.handlers[i].port {
+			continue
+		}
+		err = ps.handlers[i].demux(b, offset)
+		if err != nil {
+			break
+		}
+	}
+	ps.handleResult(i, 0, err)
+	return err
+}
+
+func (ps *StackPorts) Register(h StackNode) error {
+	port := h.LocalPort()
+	proto := h.Protocol()
+	if port <= 0 {
+		return errZeroPort
+	} else if proto != ps.protocol {
+		return errInvalidProto
+	}
+	ps.handlers = append(ps.handlers, node{
+		demux:       h.Demux,
+		encapsulate: h.Encapsulate,
+		port:        uint16(port),
+	})
+	return nil
+}
+
+func (ps *StackPorts) handleResult(handlerIdx, n int, err error) {
+	handleNodeError(&ps.handlers, handlerIdx, err)
+}