Improved readability of send/receive code

This commit is contained in:
Mathias Hall-Andersen 2017-09-09 15:03:01 +02:00
parent 89d0045214
commit f212795e51
2 changed files with 199 additions and 239 deletions

View file

@ -128,7 +128,7 @@ func (device *Device) RoutineReceiveIncomming() {
// read next datagram
size, raddr, err := conn.ReadFromUDP(buffer[:]) // Blocks sometimes
size, raddr, err := conn.ReadFromUDP(buffer[:])
if err != nil {
break
@ -222,7 +222,7 @@ func (device *Device) RoutineReceiveIncomming() {
}
func (device *Device) RoutineDecryption() {
var elem *QueueInboundElement
var nonce [chacha20poly1305.NonceSize]byte
logDebug := device.log.Debug
@ -230,10 +230,11 @@ func (device *Device) RoutineDecryption() {
for {
select {
case elem = <-device.queue.decryption:
case <-device.signal.stop:
logDebug.Println("Routine, decryption worker, stopped")
return
}
case elem := <-device.queue.decryption:
// check if dropped
@ -248,7 +249,6 @@ func (device *Device) RoutineDecryption() {
// decrypt with key-pair
var err error
copy(nonce[4:], counter)
elem.counter = binary.LittleEndian.Uint64(counter)
elem.keyPair.receive.mutex.RLock()
@ -256,6 +256,7 @@ func (device *Device) RoutineDecryption() {
// very unlikely (the key was deleted during queuing)
elem.Drop()
} else {
var err error
elem.packet, err = elem.keyPair.receive.aead.Open(
elem.buffer[:0],
nonce[:],
@ -266,14 +267,14 @@ func (device *Device) RoutineDecryption() {
elem.Drop()
}
}
elem.keyPair.receive.mutex.RUnlock()
elem.mutex.Unlock()
}
}
}
/* Handles incomming packets related to handshake
*
*
*/
func (device *Device) RoutineHandshake() {
@ -473,7 +474,6 @@ func (device *Device) RoutineHandshake() {
}
func (peer *Peer) RoutineSequentialReceiver() {
var elem *QueueInboundElement
device := peer.device
@ -483,17 +483,17 @@ func (peer *Peer) RoutineSequentialReceiver() {
logDebug.Println("Routine, sequential receiver, started for peer", peer.id)
for {
// wait for decryption
select {
case <-peer.signal.stop:
logDebug.Println("Routine, sequential receiver, stopped for peer", peer.id)
return
case elem = <-peer.queue.inbound:
}
case elem := <-peer.queue.inbound:
// wait for decryption
elem.mutex.Lock()
// process packet
if elem.IsDropped() {
continue
}
@ -597,4 +597,5 @@ func (peer *Peer) RoutineSequentialReceiver() {
logError.Println("Failed to write packet to TUN device:", err)
}
}
}
}

View file

@ -35,7 +35,7 @@ type QueueOutboundElement struct {
dropped int32
mutex sync.Mutex
buffer *[MaxMessageSize]byte // slice holding the packet data
packet []byte // slice of "data" (always!)
packet []byte // slice of "buffer" (always!)
nonce uint64 // nonce for encryption
keyPair *KeyPair // key-pair for encryption
peer *Peer // related peer
@ -52,11 +52,6 @@ func (peer *Peer) FlushNonceQueue() {
}
}
var (
ErrorNoEndpoint = errors.New("No known endpoint for peer")
ErrorNoConnection = errors.New("No UDP socket for device")
)
func (device *Device) NewOutboundElement() *QueueOutboundElement {
return &QueueOutboundElement{
dropped: AtomicFalse,
@ -118,14 +113,13 @@ func (peer *Peer) SendBuffer(buffer []byte) (int, error) {
defer peer.mutex.RUnlock()
endpoint := peer.endpoint
conn := peer.device.net.conn
if endpoint == nil {
return 0, ErrorNoEndpoint
return 0, errors.New("No known endpoint for peer")
}
conn := peer.device.net.conn
if conn == nil {
return 0, ErrorNoConnection
return 0, errors.New("No UDP socket for device")
}
return conn.WriteToUDP(buffer, endpoint)
@ -189,16 +183,6 @@ func (device *Device) RoutineReadFromTUN() {
continue
}
// check if known endpoint (drop early)
peer.mutex.RLock()
if peer.endpoint == nil {
peer.mutex.RUnlock()
logDebug.Println("No known endpoint for peer", peer.String())
continue
}
peer.mutex.RUnlock()
// insert into nonce/pre-handshake queue
signalSend(peer.signal.handshakeReset)
@ -211,86 +195,61 @@ func (device *Device) RoutineReadFromTUN() {
* Then assigns nonces to packets sequentially
* and creates "work" structs for workers
*
* TODO: Avoid dynamic allocation of work queue elements
*
* Obs. A single instance per peer
*/
func (peer *Peer) RoutineNonce() {
var keyPair *KeyPair
var elem *QueueOutboundElement
device := peer.device
logDebug := device.log.Debug
logDebug.Println("Routine, nonce worker, started for peer", peer.String())
func() {
for {
NextPacket:
// wait for packet
if elem == nil {
select {
case elem = <-peer.queue.nonce:
case <-peer.signal.stop:
return
}
}
case elem := <-peer.queue.nonce:
// wait for key pair
for {
select {
case <-peer.signal.newKeyPair:
default:
}
keyPair = peer.keyPairs.Current()
if keyPair != nil && keyPair.sendNonce < RejectAfterMessages {
if time.Now().Sub(keyPair.created) < RejectAfterTime {
break
}
}
signalSend(peer.signal.handshakeBegin)
logDebug.Println("Awaiting key-pair for", peer.String())
select {
case <-peer.signal.newKeyPair:
logDebug.Println("Key-pair negotiated for", peer.String())
goto NextPacket
case <-peer.signal.flushNonceQueue:
logDebug.Println("Clearing queue for", peer.String())
peer.FlushNonceQueue()
elem = nil
goto NextPacket
case <-peer.signal.stop:
return
}
}
// process current packet
// populate work element
if elem != nil {
// create work element
elem.keyPair = keyPair
elem.nonce = atomic.AddUint64(&keyPair.sendNonce, 1) - 1
elem.dropped = AtomicFalse
elem.peer = peer
elem.nonce = atomic.AddUint64(&keyPair.sendNonce, 1) - 1
elem.keyPair = keyPair
elem.dropped = AtomicFalse
elem.mutex.Lock()
// add to parallel and sequential queue
addToEncryptionQueue(device.queue.encryption, elem)
addToOutboundQueue(peer.queue.outbound, elem)
elem = nil
}
}
}()
}
/* Encrypts the elements in the queue
@ -300,7 +259,6 @@ func (peer *Peer) RoutineNonce() {
*/
func (device *Device) RoutineEncryption() {
var elem *QueueOutboundElement
var nonce [chacha20poly1305.NonceSize]byte
logDebug := device.log.Debug
@ -311,11 +269,11 @@ func (device *Device) RoutineEncryption() {
// fetch next element
select {
case elem = <-device.queue.encryption:
case <-device.signal.stop:
logDebug.Println("Routine, encryption worker, stopped")
return
}
case elem := <-device.queue.encryption:
// check if dropped
@ -335,15 +293,14 @@ func (device *Device) RoutineEncryption() {
binary.LittleEndian.PutUint32(fieldReceiver, elem.keyPair.remoteIndex)
binary.LittleEndian.PutUint64(fieldNonce, elem.nonce)
// pad content to MTU size
// pad content to multiple of 16
mtu := int(atomic.LoadInt32(&device.tun.mtu))
pad := len(elem.packet) % PaddingMultiple
if pad > 0 {
for i := 0; i < PaddingMultiple-pad && len(elem.packet) < mtu; i++ {
rem := len(elem.packet) % PaddingMultiple
if rem > 0 {
for i := 0; i < PaddingMultiple-rem && len(elem.packet) < mtu; i++ {
elem.packet = append(elem.packet, 0)
}
// TODO: How good is this code
}
// encrypt content (append to header)
@ -361,13 +318,14 @@ func (device *Device) RoutineEncryption() {
nil,
)
}
elem.keyPair.send.mutex.RUnlock()
elem.mutex.Unlock()
elem.keyPair.send.mutex.RUnlock()
// refresh key if necessary
elem.peer.KeepKeyFreshSending()
}
}
}
/* Sequentially reads packets from queue and sends to endpoint
@ -399,6 +357,7 @@ func (peer *Peer) RoutineSequentialSender() {
_, err := peer.SendBuffer(elem.packet)
device.PutMessageBuffer(elem.buffer)
if err != nil {
logDebug.Println("Failed to send authenticated packet to peer", peer.String())
continue
}
atomic.AddUint64(&peer.stats.txBytes, length)