Update MTU based on netlink messages (linux)

This commit is contained in:
Mathias Hall-Andersen 2017-08-22 14:57:32 +02:00
parent 04640eb629
commit c6d03ef17f
3 changed files with 43 additions and 41 deletions

View file

@ -176,43 +176,6 @@ func NewDevice(tun TUNDevice, logLevel int) *Device {
return device
}
func (device *Device) RoutineTUNEventReader() {
logInfo := device.log.Info
logError := device.log.Error
events := device.tun.device.Events()
for event := range events {
if event&TUNEventMTUUpdate != 0 {
mtu, err := device.tun.device.MTU()
if err != nil {
logError.Println("Failed to load updated MTU of device:", err)
} else {
if mtu+MessageTransportSize > MaxMessageSize {
mtu = MaxMessageSize - MessageTransportSize
}
atomic.StoreInt32(&device.tun.mtu, int32(mtu))
}
}
if event&TUNEventUp != 0 {
if !device.tun.isUp.Get() {
device.tun.isUp.Set(true)
updateUDPConn(device)
logInfo.Println("Interface set up")
}
}
if event&TUNEventDown != 0 {
if device.tun.isUp.Get() {
device.tun.isUp.Set(false)
closeUDPConn(device)
logInfo.Println("Interface set down")
}
}
}
}
func (device *Device) LookupPeer(pk NoisePublicKey) *Peer {
device.mutex.RLock()
defer device.mutex.RUnlock()

View file

@ -1,8 +1,8 @@
package main
/*
* The default MTU of the new device must be 1420
*/
import (
"sync/atomic"
)
const DefaultMTU = 1420
@ -22,3 +22,41 @@ type TUNDevice interface {
Events() chan TUNEvent // returns a constant channel of events related to the device
Close() error // stops the device and closes the event channel
}
func (device *Device) RoutineTUNEventReader() {
logInfo := device.log.Info
logError := device.log.Error
for event := range device.tun.device.Events() {
if event&TUNEventMTUUpdate != 0 {
mtu, err := device.tun.device.MTU()
old := atomic.LoadInt32(&device.tun.mtu)
if err != nil {
logError.Println("Failed to load updated MTU of device:", err)
} else if int(old) != mtu {
atomic.StoreInt32(&device.tun.mtu, int32(mtu))
if mtu+MessageTransportSize > MaxMessageSize {
logInfo.Println("MTU updated:", mtu, "(too large)")
} else {
logInfo.Println("MTU updated:", mtu)
}
}
}
if event&TUNEventUp != 0 {
if !device.tun.isUp.Get() {
device.tun.isUp.Set(true)
updateUDPConn(device)
logInfo.Println("Interface set up")
}
}
if event&TUNEventDown != 0 {
if device.tun.isUp.Get() {
device.tun.isUp.Set(false)
closeUDPConn(device)
logInfo.Println("Interface set down")
}
}
}
}

View file

@ -85,6 +85,7 @@ func (tun *NativeTun) RoutineNetlinkListener() {
case unix.RTM_NEWLINK:
info := *(*unix.IfInfomsg)(unsafe.Pointer(&remain[unix.SizeofNlMsghdr]))
remain = remain[hdr.Len:]
if info.Index != tun.index {
// not our interface
@ -99,7 +100,7 @@ func (tun *NativeTun) RoutineNetlinkListener() {
tun.events <- TUNEventDown
}
remain = remain[hdr.Len:]
tun.events <- TUNEventMTUUpdate
default:
remain = remain[hdr.Len:]