add ARP; add tap internal calls; more lneto2 additions

arp/definitions.go

@@ -0,0 +1,25 @@
+package arp
+
+import "errors"
+
+//go:generate stringer -type=Operation -linecomment -output stringers.go .
+
+const (
+	sizeHeader   = 8
+	sizeHeaderv4 = sizeHeader + 6*2 + 4*2
+	sizeHeaderv6 = sizeHeader + 6*2 + 16*2
+)
+
+var (
+	errARPBufferFull  = errors.New("ARP client need handling:too many ops pending")
+	errShortARP       = errors.New("packet too short to be ARP")
+	errARPUnsupported = errors.New("ARP not supprortedf")
+)
+
+// Operation represents the type of ARP packet, either request or reply/response.
+type Operation uint8
+
+const (
+	OpRequest Operation = 1 // request
+	OpReply   Operation = 2 // reply
+)