Mathias Hall-Andersen
5f01086f19
An update of the fwmark was missing, when the device was not bought up after the change.
71 lines
1.9 KiB
Go
71 lines
1.9 KiB
Go
package main
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import (
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"os"
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"sync/atomic"
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)
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const DefaultMTU = 1420
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type TUNEvent int
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const (
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TUNEventUp = 1 << iota
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TUNEventDown
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TUNEventMTUUpdate
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)
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type TUNDevice interface {
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File() *os.File // returns the file descriptor of the device
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Read([]byte, int) (int, error) // read a packet from the device (without any additional headers)
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Write([]byte, int) (int, error) // writes a packet to the device (without any additional headers)
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MTU() (int, error) // returns the MTU of the device
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Name() string // returns the current name
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Events() chan TUNEvent // returns a constant channel of events related to the device
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Close() error // stops the device and closes the event channel
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}
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func (device *Device) RoutineTUNEventReader() {
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logInfo := device.log.Info
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logError := device.log.Error
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for event := range device.tun.device.Events() {
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if event&TUNEventMTUUpdate != 0 {
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mtu, err := device.tun.device.MTU()
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old := atomic.LoadInt32(&device.tun.mtu)
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if err != nil {
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logError.Println("Failed to load updated MTU of device:", err)
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} else if int(old) != mtu {
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if mtu+MessageTransportSize > MaxMessageSize {
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logInfo.Println("MTU updated:", mtu, "(too large)")
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} else {
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logInfo.Println("MTU updated:", mtu)
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}
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atomic.StoreInt32(&device.tun.mtu, int32(mtu))
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}
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}
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if event&TUNEventUp != 0 {
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if !device.tun.isUp.Get() {
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// begin listening for incomming datagrams
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logInfo.Println("Interface set up")
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device.tun.isUp.Set(true)
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if err := updateBind(device); err != nil {
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logInfo.Println("Failed to bind UDP socket:", err)
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}
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}
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}
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if event&TUNEventDown != 0 {
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if device.tun.isUp.Get() {
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// stop listening for incomming datagrams
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logInfo.Println("Interface set down")
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device.tun.isUp.Set(false)
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if err := closeBind(device); err != nil {
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logInfo.Println("Failed to close UDP socket:", err)
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}
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}
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}
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}
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}
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