Add round-robin implementation (#66)

* add handler.encapsulateNode

* implement round robin handler approach

* simplify round robin implementation

* leave TODO

* internet.node touch up

* fix conflict resolve f-up

* replace certain ErrShortBuffer with ErrTruncatedFrame error

arp/definitions.go

@@ -19,8 +19,7 @@ var (
 	errQueryNotFound = errors.New("arp: query not found")
 
 	// errGeneric aliases for common ARP errors.
-	errARPBufferFull  = lneto.ErrBufferFull
-	errShortARP       = lneto.ErrShortBuffer
+	errShortARP       = lneto.ErrTruncatedFrame
 	errARPUnsupported = lneto.ErrUnsupported
 	errLargeSizes     = lneto.ErrPacketDrop
 )

arp/frame.go

@@ -10,13 +10,13 @@ import (
 	"github.com/soypat/lneto/ethernet"
 )
 
-// NewARPFrame returns a ARPFrame with data set to buf.
+// NewFrame returns a Frame with data set to buf.
 // An error is returned if the buffer size is smaller than 28 (IPv4 min size).
-// Users should still call [ARPFrame.ValidateSize] before working
+// Users should still call [Frame.ValidateSize] before working
 // with payload/options of frames to avoid panics.
 func NewFrame(buf []byte) (Frame, error) {
 	if len(buf) < sizeHeaderv4 {
-		return Frame{buf: nil}, lneto.ErrShortBuffer
+		return Frame{buf: nil}, lneto.ErrTruncatedFrame
 	}
 	return Frame{buf: buf}, nil
 }

arp/handler.go

@@ -149,7 +149,7 @@ func (h *Handler) StartQuery(dstHWAddr, proto []byte) error {
 	if len(h.queries) == cap(h.queries) {
 		h.compactQueries()
 		if len(h.queries) == cap(h.queries) {
-			return lneto.ErrBufferFull
+			return lneto.ErrExhausted
 		}
 	}
 	if len(proto) != len(h.ourProtoAddr) {
@@ -214,7 +214,7 @@ func (h *Handler) Encapsulate(carrierData []byte, offsetToIP, offsetToFrame int)
 
 func (h *Handler) Demux(ethFrame []byte, frameOffset int) error {
 	if len(h.pendingResponse) == cap(h.pendingResponse) {
-		return errARPBufferFull
+		return lneto.ErrExhausted
 	}
 
 	b := ethFrame[frameOffset:]