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5041800ac6
At some point faketun got implemented as a loopback (put a packet in from wireguard, the same packet goes back to wireguard) which is not useful. It's supposed to be an interface that just sinks all packets, and then wgengine adds *only* and ICMP Echo responder as a layer on top. This caused extremely odd bugs on darwin, where the special case that reinjects packets from local->local was filling the loopback channel and creating an infinite loop (which became jammed since the reader and writer were in the same goroutine). Signed-off-by: Avery Pennarun <apenwarr@tailscale.com>
57 lines
1.2 KiB
Go
57 lines
1.2 KiB
Go
// Copyright (c) 2020 Tailscale Inc & AUTHORS All rights reserved.
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// Use of this source code is governed by a BSD-style
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// license that can be found in the LICENSE file.
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package tstun
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import (
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"io"
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"os"
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"github.com/tailscale/wireguard-go/tun"
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)
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type fakeTUN struct {
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evchan chan tun.Event
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closechan chan struct{}
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}
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// NewFakeTUN returns a fake TUN device that does not depend on the
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// operating system or any special permissions.
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// It primarily exists for testing.
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func NewFakeTUN() tun.Device {
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return &fakeTUN{
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evchan: make(chan tun.Event),
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closechan: make(chan struct{}),
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}
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}
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func (t *fakeTUN) File() *os.File {
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panic("fakeTUN.File() called, which makes no sense")
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}
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func (t *fakeTUN) Close() error {
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close(t.closechan)
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close(t.evchan)
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return nil
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}
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func (t *fakeTUN) Read(out []byte, offset int) (int, error) {
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<-t.closechan
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return 0, io.EOF
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}
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func (t *fakeTUN) Write(b []byte, n int) (int, error) {
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select {
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case <-t.closechan:
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return 0, ErrClosed
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default:
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}
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return len(b), nil
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}
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func (t *fakeTUN) Flush() error { return nil }
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func (t *fakeTUN) MTU() (int, error) { return 1500, nil }
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func (t *fakeTUN) Name() (string, error) { return "FakeTUN", nil }
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func (t *fakeTUN) Events() chan tun.Event { return t.evchan }
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