nebula/overlay/tun_tester.go

137 lines
3.1 KiB
Go

//go:build e2e_testing
// +build e2e_testing
package overlay
import (
"fmt"
"io"
"net/netip"
"os"
"sync/atomic"
"github.com/gaissmai/bart"
"github.com/sirupsen/logrus"
"github.com/slackhq/nebula/config"
)
type TestTun struct {
Device string
cidr netip.Prefix
Routes []Route
routeTree *bart.Table[netip.Addr]
l *logrus.Logger
closed atomic.Bool
rxPackets chan []byte // Packets to receive into nebula
TxPackets chan []byte // Packets transmitted outside by nebula
}
func newTun(c *config.C, l *logrus.Logger, cidr netip.Prefix, _ bool) (*TestTun, error) {
_, routes, err := getAllRoutesFromConfig(c, cidr, true)
if err != nil {
return nil, err
}
routeTree, err := makeRouteTree(l, routes, false)
if err != nil {
return nil, err
}
return &TestTun{
Device: c.GetString("tun.dev", ""),
cidr: cidr,
Routes: routes,
routeTree: routeTree,
l: l,
rxPackets: make(chan []byte, 10),
TxPackets: make(chan []byte, 10),
}, nil
}
func newTunFromFd(_ *config.C, _ *logrus.Logger, _ int, _ netip.Prefix) (*TestTun, 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 (t *TestTun) Send(packet []byte) {
if t.closed.Load() {
return
}
if t.l.Level >= logrus.DebugLevel {
t.l.WithField("dataLen", len(packet)).Debug("Tun receiving injected packet")
}
t.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 (t *TestTun) Get(block bool) []byte {
if block {
return <-t.TxPackets
}
select {
case p := <-t.TxPackets:
return p
default:
return nil
}
}
//********************************************************************************************************************//
// Below this is boilerplate implementation to make nebula actually work
//********************************************************************************************************************//
func (t *TestTun) RouteFor(ip netip.Addr) netip.Addr {
r, _ := t.routeTree.Lookup(ip)
return r
}
func (t *TestTun) Activate() error {
return nil
}
func (t *TestTun) Cidr() netip.Prefix {
return t.cidr
}
func (t *TestTun) Name() string {
return t.Device
}
func (t *TestTun) Write(b []byte) (n int, err error) {
if t.closed.Load() {
return 0, io.ErrClosedPipe
}
packet := make([]byte, len(b), len(b))
copy(packet, b)
t.TxPackets <- packet
return len(b), nil
}
func (t *TestTun) Close() error {
if t.closed.CompareAndSwap(false, true) {
close(t.rxPackets)
close(t.TxPackets)
}
return nil
}
func (t *TestTun) Read(b []byte) (int, error) {
p, ok := <-t.rxPackets
if !ok {
return 0, os.ErrClosed
}
copy(b, p)
return len(p), nil
}
func (t *TestTun) NewMultiQueueReader() (io.ReadWriteCloser, error) {
return nil, fmt.Errorf("TODO: multiqueue not implemented")
}