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|
package main
import (
"net"
"runtime"
"sync"
"sync/atomic"
"time"
)
type Device struct {
log *Logger // collection of loggers for levels
idCounter uint // for assigning debug ids to peers
fwMark uint32
tun struct {
device TUNDevice
isUp AtomicBool
mtu int32
}
pool struct {
messageBuffers sync.Pool
}
net struct {
mutex sync.RWMutex
addr *net.UDPAddr // UDP source address
conn *net.UDPConn // UDP "connection"
}
mutex sync.RWMutex
privateKey NoisePrivateKey
publicKey NoisePublicKey
routingTable RoutingTable
indices IndexTable
queue struct {
encryption chan *QueueOutboundElement
decryption chan *QueueInboundElement
handshake chan QueueHandshakeElement
}
signal struct {
stop chan struct{} // halts all go routines
newUDPConn chan struct{} // a net.conn was set (consumed by the receiver routine)
}
underLoadUntil atomic.Value
ratelimiter Ratelimiter
peers map[NoisePublicKey]*Peer
mac MACStateDevice
}
/* Warning:
* The caller must hold the device mutex (write lock)
*/
func removePeerUnsafe(device *Device, key NoisePublicKey) {
peer, ok := device.peers[key]
if !ok {
return
}
peer.mutex.Lock()
device.routingTable.RemovePeer(peer)
delete(device.peers, key)
peer.Close()
}
func (device *Device) IsUnderLoad() bool {
// check if currently under load
now := time.Now()
underLoad := len(device.queue.handshake) >= UnderLoadQueueSize
if underLoad {
device.underLoadUntil.Store(now.Add(time.Second))
return true
}
// check if recently under load
until := device.underLoadUntil.Load().(time.Time)
return until.After(now)
}
func (device *Device) SetPrivateKey(sk NoisePrivateKey) error {
device.mutex.Lock()
defer device.mutex.Unlock()
// remove peers with matching public keys
publicKey := sk.publicKey()
for key, peer := range device.peers {
h := &peer.handshake
h.mutex.RLock()
if h.remoteStatic.Equals(publicKey) {
removePeerUnsafe(device, key)
}
h.mutex.RUnlock()
}
// update key material
device.privateKey = sk
device.publicKey = publicKey
device.mac.Init(publicKey)
// do DH precomputations
rmKey := device.privateKey.IsZero()
for key, peer := range device.peers {
h := &peer.handshake
h.mutex.Lock()
if rmKey {
h.precomputedStaticStatic = [NoisePublicKeySize]byte{}
} else {
h.precomputedStaticStatic = device.privateKey.sharedSecret(h.remoteStatic)
if isZero(h.precomputedStaticStatic[:]) {
removePeerUnsafe(device, key)
}
}
h.mutex.Unlock()
}
return nil
}
func (device *Device) GetMessageBuffer() *[MaxMessageSize]byte {
return device.pool.messageBuffers.Get().(*[MaxMessageSize]byte)
}
func (device *Device) PutMessageBuffer(msg *[MaxMessageSize]byte) {
device.pool.messageBuffers.Put(msg)
}
func NewDevice(tun TUNDevice, logLevel int) *Device {
device := new(Device)
device.mutex.Lock()
defer device.mutex.Unlock()
device.log = NewLogger(logLevel, "("+tun.Name()+") ")
device.peers = make(map[NoisePublicKey]*Peer)
device.tun.device = tun
device.indices.Init()
device.ratelimiter.Init()
device.routingTable.Reset()
device.underLoadUntil.Store(time.Time{})
// setup pools
device.pool.messageBuffers = sync.Pool{
New: func() interface{} {
return new([MaxMessageSize]byte)
},
}
// create queues
device.queue.handshake = make(chan QueueHandshakeElement, QueueHandshakeSize)
device.queue.encryption = make(chan *QueueOutboundElement, QueueOutboundSize)
device.queue.decryption = make(chan *QueueInboundElement, QueueInboundSize)
// prepare signals
device.signal.stop = make(chan struct{})
device.signal.newUDPConn = make(chan struct{}, 1)
// start workers
for i := 0; i < runtime.NumCPU(); i += 1 {
go device.RoutineEncryption()
go device.RoutineDecryption()
go device.RoutineHandshake()
}
go device.RoutineTUNEventReader()
go device.ratelimiter.RoutineGarbageCollector(device.signal.stop)
go device.RoutineReadFromTUN()
go device.RoutineReceiveIncomming()
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 {
device.tun.isUp.Set(true)
updateUDPConn(device)
logInfo.Println("Interface set up")
}
if event&TUNEventDown != 0 {
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()
return device.peers[pk]
}
func (device *Device) RemovePeer(key NoisePublicKey) {
device.mutex.Lock()
defer device.mutex.Unlock()
removePeerUnsafe(device, key)
}
func (device *Device) RemoveAllPeers() {
device.mutex.Lock()
defer device.mutex.Unlock()
for key, peer := range device.peers {
peer.mutex.Lock()
delete(device.peers, key)
peer.Close()
peer.mutex.Unlock()
}
}
func (device *Device) Close() {
device.RemoveAllPeers()
close(device.signal.stop)
closeUDPConn(device)
}
func (device *Device) WaitChannel() chan struct{} {
return device.signal.stop
}
|
