tailscale/wgengine/faketun.go

61 lines
1.5 KiB
Go

// Copyright (c) 2020 Tailscale Inc & AUTHORS All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package wgengine
import (
"io"
"os"
"github.com/tailscale/wireguard-go/tun"
)
type fakeTun struct {
datachan chan []byte
evchan chan tun.Event
closechan chan struct{}
}
// NewFakeTun returns a fake TUN device that does not depend on the
// operating system or any special permissions.
// It primarily exists for testing.
func NewFakeTun() tun.Device {
return &fakeTun{
datachan: make(chan []byte),
evchan: make(chan tun.Event),
closechan: make(chan struct{}),
}
}
func (t *fakeTun) File() *os.File {
panic("fakeTun.File() called, which makes no sense")
}
func (t *fakeTun) Close() error {
close(t.closechan)
close(t.datachan)
close(t.evchan)
return nil
}
func (t *fakeTun) InsertRead(b []byte) {
t.datachan <- b
}
func (t *fakeTun) Read(out []byte, offset int) (int, error) {
select {
case <-t.closechan:
return 0, io.EOF
case b := <-t.datachan:
copy(out[offset:offset+len(b)], b)
return len(b), nil
}
}
func (t *fakeTun) Write(b []byte, n int) (int, error) { return len(b), nil }
func (t *fakeTun) Flush() error { return nil }
func (t *fakeTun) MTU() (int, error) { return 1500, nil }
func (t *fakeTun) Name() (string, error) { return "FakeTun", nil }
func (t *fakeTun) Events() chan tun.Event { return t.evchan }