wireguard-go/device/tun.go

55 lines
1.2 KiB
Go

/* SPDX-License-Identifier: MIT
*
* Copyright (C) 2017-2021 WireGuard LLC. All Rights Reserved.
*/
package device
import (
"fmt"
"sync/atomic"
"golang.zx2c4.com/wireguard/tun"
)
const DefaultMTU = 1420
func (device *Device) RoutineTUNEventReader() {
device.log.Verbosef("Routine: event worker - started")
for event := range device.tun.device.Events() {
if event&tun.EventMTUUpdate != 0 {
mtu, err := device.tun.device.MTU()
if err != nil {
device.log.Errorf("Failed to load updated MTU of device: %v", err)
continue
}
if mtu < 0 {
device.log.Errorf("MTU not updated to negative value: %v", mtu)
continue
}
var tooLarge string
if mtu > MaxContentSize {
tooLarge = fmt.Sprintf(" (too large, capped at %v)", MaxContentSize)
mtu = MaxContentSize
}
old := atomic.SwapInt32(&device.tun.mtu, int32(mtu))
if int(old) != mtu {
device.log.Verbosef("MTU updated: %v%s", mtu, tooLarge)
}
}
if event&tun.EventUp != 0 {
device.log.Verbosef("Interface up requested")
device.Up()
}
if event&tun.EventDown != 0 {
device.log.Verbosef("Interface down requested")
device.Down()
}
}
device.log.Verbosef("Routine: event worker - stopped")
}