Move all of tun into overlay (#577)

overlay/tun_tester.go

@@ -0,0 +1,105 @@
+//go:build e2e_testing
+// +build e2e_testing
+
+package overlay
+
+import (
+	"fmt"
+	"io"
+	"net"
+
+	"github.com/sirupsen/logrus"
+)
+
+type Tun struct {
+	Device       string
+	Cidr         *net.IPNet
+	MTU          int
+	UnsafeRoutes []Route
+	l            *logrus.Logger
+
+	rxPackets chan []byte // Packets to receive into nebula
+	TxPackets chan []byte // Packets transmitted outside by nebula
+}
+
+func newTun(l *logrus.Logger, deviceName string, cidr *net.IPNet, defaultMTU int, _ []Route, unsafeRoutes []Route, _ int, _ bool) (ifce *Tun, err error) {
+	return &Tun{
+		Device:       deviceName,
+		Cidr:         cidr,
+		MTU:          defaultMTU,
+		UnsafeRoutes: unsafeRoutes,
+		l:            l,
+		rxPackets:    make(chan []byte, 1),
+		TxPackets:    make(chan []byte, 1),
+	}, nil
+}
+
+func newTunFromFd(_ *logrus.Logger, _ int, _ *net.IPNet, _ int, _ []Route, _ []Route, _ int) (ifce *Tun, err error) {
+	return nil, fmt.Errorf("newTunFromFd not supported")
+}
+
+// Send will place a byte array onto the receive queue for nebula to consume
+// These are unencrypted ip layer frames destined for another nebula node.
+// packets should exit the udp side, capture them with udpConn.Get
+func (c *Tun) Send(packet []byte) {
+	c.l.WithField("dataLen", len(packet)).Info("Tun receiving injected packet")
+	c.rxPackets <- packet
+}
+
+// Get will pull an unencrypted ip layer frame from the transmit queue
+// nebula meant to send this message to some application on the local system
+// packets were ingested from the udp side, you can send them with udpConn.Send
+func (c *Tun) Get(block bool) []byte {
+	if block {
+		return <-c.TxPackets
+	}
+
+	select {
+	case p := <-c.TxPackets:
+		return p
+	default:
+		return nil
+	}
+}
+
+//********************************************************************************************************************//
+// Below this is boilerplate implementation to make nebula actually work
+//********************************************************************************************************************//
+
+func (c *Tun) Activate() error {
+	return nil
+}
+
+func (c *Tun) CidrNet() *net.IPNet {
+	return c.Cidr
+}
+
+func (c *Tun) DeviceName() string {
+	return c.Device
+}
+
+func (c *Tun) Write(b []byte) (n int, err error) {
+	return len(b), c.WriteRaw(b)
+}
+
+func (c *Tun) Close() error {
+	close(c.rxPackets)
+	return nil
+}
+
+func (c *Tun) WriteRaw(b []byte) error {
+	packet := make([]byte, len(b), len(b))
+	copy(packet, b)
+	c.TxPackets <- packet
+	return nil
+}
+
+func (c *Tun) Read(b []byte) (int, error) {
+	p := <-c.rxPackets
+	copy(b, p)
+	return len(p), nil
+}
+
+func (c *Tun) NewMultiQueueReader() (io.ReadWriteCloser, error) {
+	return nil, fmt.Errorf("TODO: multiqueue not implemented")
+}