snow/wireguard-go
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device: remove QueueInboundElement.dropped

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Now that we block when enqueueing to the decryption queue,
there is only one case in which we "drop" a inbound element,
when decryption fails.

We can use a simple, obvious, sync-free sentinel for that, elem.packet == nil.
Also, we can return the message buffer to the pool slightly later,
which further simplifies the code.

Signed-off-by: Josh Bleecher Snyder <josh@tailscale.com>
This commit is contained in:
Josh Bleecher Snyder 2021-01-17 09:49:39 -08:00 committed by Jason A. Donenfeld
parent 7ee95e053c
commit a86492a567
1 changed files with 5 additions and 30 deletions
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31
device/receive.go
View file

@ -30,7 +30,6 @@ type QueueHandshakeElement struct {
}
type QueueInboundElement struct {
dropped int32
sync.Mutex
buffer *[MaxMessageSize]byte
packet []byte
@ -50,14 +49,6 @@ func (elem *QueueInboundElement) clearPointers() {
elem.endpoint = nil
}
func (elem *QueueInboundElement) Drop() {
atomic.StoreInt32(&elem.dropped, AtomicTrue)
}
func (elem *QueueInboundElement) IsDropped() bool {
return atomic.LoadInt32(&elem.dropped) == AtomicTrue
}
func (device *Device) addToHandshakeQueue(queue chan QueueHandshakeElement, elem QueueHandshakeElement) bool {
select {
case queue <- elem:
@ -180,7 +171,6 @@ func (device *Device) RoutineReceiveIncoming(IP int, bind conn.Bind) {
elem.packet = packet
elem.buffer = buffer
elem.keypair = keypair
elem.dropped = AtomicFalse
elem.endpoint = endpoint
elem.counter = 0
elem.Mutex = sync.Mutex{}
@ -243,19 +233,11 @@ func (device *Device) RoutineDecryption() {
logDebug.Println("Routine: decryption worker - started")
for elem := range device.queue.decryption.c {
// check if dropped
if elem.IsDropped() {
continue
}
// split message into fields
counter := elem.packet[MessageTransportOffsetCounter:MessageTransportOffsetContent]
content := elem.packet[MessageTransportOffsetContent:]
// decrypt and release to consumer
var err error
elem.counter = binary.LittleEndian.Uint64(counter)
// copy counter to nonce
@ -267,8 +249,7 @@ func (device *Device) RoutineDecryption() {
nil,
)
if err != nil {
elem.Drop()
device.PutMessageBuffer(elem.buffer)
elem.packet = nil
}
elem.Unlock()
}
@ -484,9 +465,7 @@ func (peer *Peer) RoutineSequentialReceiver() {
logDebug.Println(peer, "- Routine: sequential receiver - stopped")
peer.routines.stopping.Done()
if elem != nil {
if !elem.IsDropped() {
device.PutMessageBuffer(elem.buffer)
}
device.PutInboundElement(elem)
}
}()
@ -495,9 +474,7 @@ func (peer *Peer) RoutineSequentialReceiver() {
for {
if elem != nil {
if !elem.IsDropped() {
device.PutMessageBuffer(elem.buffer)
}
device.PutInboundElement(elem)
elem = nil
}
@ -513,15 +490,13 @@ func (peer *Peer) RoutineSequentialReceiver() {
}
// wait for decryption
elem.Lock()
if elem.IsDropped() {
if elem.packet == nil {
// decryption failed
continue
}
// check for replay
if !elem.keypair.replayFilter.ValidateCounter(elem.counter, RejectAfterMessages) {
continue
}