ethernet: refactor VLAN API

ethernet/frame.go

@@ -76,9 +76,6 @@ func (efrm Frame) SetEtherType(v Type) {
 	binary.BigEndian.PutUint16(efrm.buf[12:14], uint16(v))
 }
 
-// VLANTag returns the VLAN tag field following the TPID=0x8100. See [VLANTag]. Call [Frame.ValidateSize] to ensure this function does not panic.
-func (efrm Frame) VLANTag() VLANTag { return VLANTag(binary.BigEndian.Uint16(efrm.buf[14:16])) }
-
 // SetVLAN sets following 3 fields:
 //   - 12:14 ethernet frame type set to constant [TypeVLAN].
 //   - 14:16 set to VLANTag argument value vt
@@ -97,19 +94,6 @@ func (efrm Frame) VLAN() (VLANTag, Type) {
 	return VLANTag(vt), Type(et)
 }
 
-// SetVLANTag sets the VLAN tag field of the Ethernet Header. See [VLANTag]. Call [Frame.ValidateSize] to ensure this function does not panic.
-func (efrm Frame) SetVLANTag(vt VLANTag) { binary.BigEndian.PutUint16(efrm.buf[14:16], uint16(vt)) }
-
-// VLANEtherType returns the [EtherType] for a VLAN ethernet frame (octet position 16). Call [Frame.ValidateSize] to ensure this function does not panic.
-func (efrm Frame) VLANEtherType() Type {
-	return Type(binary.BigEndian.Uint16(efrm.buf[16:18]))
-}
-
-// SetVLANEtherType sets the [EtherType] for a VLAN ethernet frame (octet position 16). Call [Frame.ValidateSize] to ensure this function does not panic.
-func (efrm Frame) SetVLANEtherType(vt Type) {
-	binary.BigEndian.PutUint16(efrm.buf[16:18], uint16(vt))
-}
-
 // IsVLAN returns true if the SizeOrEtherType is set to the VLAN tag 0x8100. This
 // indicates the EthernetHeader is invalid as-is and instead of EtherType the field
 // contains the first two octets of a 4 octet 802.1Q VLAN tag. In this case 4 more bytes

internal/ltesto/ltesto.go

@@ -45,7 +45,7 @@ func (gen *PacketGen) AppendRandomIPv4TCPPacket(dst []byte, rng *rand.Rand, seg
 	}
 	ri := rng.Int()
 	var (
-		isVLAN    = ri&(1<<0) != 0
+		isVLAN    = gen.EnableVLAN && ri&(1<<0) != 0
 		hasIPOpt  = ri&(1<<1) != 0
 		hasTCPOpt = ri&(1<<2) != 0
 	)
@@ -55,8 +55,7 @@ func (gen *PacketGen) AppendRandomIPv4TCPPacket(dst []byte, rng *rand.Rand, seg
 		ipOpts = []byte{1, 2, 3, 4}
 	}
 	ethsize := 14
-	if gen.EnableVLAN && isVLAN {
+	if isVLAN {
-		etherType = ethernet.TypeVLAN
 		ethsize = 18
 	}
 	var tcpOpts []byte
@@ -75,10 +74,10 @@ func (gen *PacketGen) AppendRandomIPv4TCPPacket(dst []byte, rng *rand.Rand, seg
 	*efrm.DestinationHardwareAddr() = gen.DstMAC
 	*efrm.SourceHardwareAddr() = gen.SrcMAC
 
-	efrm.SetEtherType(etherType)
 	if isVLAN {
-		efrm.SetVLANEtherType(ethernet.TypeIPv4)
+		efrm.SetVLAN(1<<4, ethernet.TypeIPv4)
-		efrm.SetVLANTag(1 << 4)
+	} else {
+		efrm.SetEtherType(etherType)
 	}
 	ethernetPayload := efrm.Payload()
 	ifrm, err := ipv4.NewFrame(ethernetPayload)

lneto_test.go

@@ -58,11 +58,9 @@ func testMoveTCPPacket(t *testing.T, src, dst []byte) {
 	*efrm2.DestinationHardwareAddr() = *efrm.DestinationHardwareAddr()
 	*efrm2.SourceHardwareAddr() = *efrm.SourceHardwareAddr()
 	efrm2.SetEtherType(efrm.EtherTypeOrSize())
-	if efrm.EtherTypeOrSize() == ethernet.TypeVLAN {
+	if efrm.IsVLAN() {
-		efrm2.SetVLANTag(efrm.VLANTag())
+		efrm2.SetVLAN(efrm.VLAN())
-		efrm2.SetVLANEtherType(efrm.VLANEtherType())
 	}
-
 	ifrm2, _ := ipv4.NewFrame(efrm2.Payload())
 	ifrm2.SetVersionAndIHL(ifrm.VersionAndIHL())
 	ifrm2.SetToS(ifrm.ToS())