delete 0-RTT queues if no Initial is received within 100ms

internal/protocol/params.go

@@ -159,6 +159,9 @@ const MaxAckDelayInclGranularity = MaxAckDelay + TimerGranularity
 // KeyUpdateInterval is the maximum number of packets we send or receive before initiating a key udpate.
 const KeyUpdateInterval = 100 * 1000
 
+// Max0RTTQueueingDuration is the maximum time that we store 0-RTT packets in order to wait for the corresponding Initial to be received.
+const Max0RTTQueueingDuration = 100 * time.Millisecond
+
 // Max0RTTQueues is the maximum number of connections that we buffer 0-RTT packets for.
 const Max0RTTQueues = 32
 

zero_rtt_queue.go

@@ -2,17 +2,23 @@ package quic
 
 import (
 	"sync"
+	"time"
 
 	"github.com/lucas-clemente/quic-go/internal/protocol"
 )
 
+type zeroRTTQueueEntry struct {
+	timer   *time.Timer
+	packets []*receivedPacket
+}
+
 type zeroRTTQueue struct {
 	mutex sync.Mutex
-	queue map[string][]*receivedPacket
+	queue map[string]*zeroRTTQueueEntry
 }
 
 func newZeroRTTQueue() *zeroRTTQueue {
-	return &zeroRTTQueue{queue: make(map[string][]*receivedPacket)}
+	return &zeroRTTQueue{queue: make(map[string]*zeroRTTQueueEntry)}
 }
 
 func (h *zeroRTTQueue) Enqueue(connID protocol.ConnectionID, p *receivedPacket) {
@@ -20,27 +26,36 @@ func (h *zeroRTTQueue) Enqueue(connID protocol.ConnectionID, p *receivedPacket)
 	defer h.mutex.Unlock()
 
 	cid := string(connID)
-	if _, ok := h.queue[cid]; !ok && len(h.queue) >= protocol.Max0RTTQueues {
+	if _, ok := h.queue[cid]; !ok {
+		if len(h.queue) >= protocol.Max0RTTQueues {
+			return
+		}
+		h.queue[cid] = &zeroRTTQueueEntry{timer: time.AfterFunc(protocol.Max0RTTQueueingDuration, func() {
+			h.mutex.Lock()
+			delete(h.queue, cid)
+			h.mutex.Unlock()
+		})}
+	}
+	entry := h.queue[cid]
+	if len(entry.packets) >= protocol.Max0RTTQueueLen {
 		return
 	}
-	if len(h.queue[cid]) >= protocol.Max0RTTQueueLen {
-		return
-	}
-	h.queue[cid] = append(h.queue[cid], p)
+	entry.packets = append(entry.packets, p)
 }
 
 func (h *zeroRTTQueue) Dequeue(connID protocol.ConnectionID) *receivedPacket {
 	h.mutex.Lock()
 	defer h.mutex.Unlock()
 
-	cid := string(connID)
-	if _, ok := h.queue[cid]; !ok {
+	entry, ok := h.queue[string(connID)]
+	if !ok {
 		return nil
 	}
-	p := h.queue[cid][0]
-	h.queue[cid] = h.queue[cid][1:]
-	if len(h.queue[cid]) == 0 {
-		delete(h.queue, cid)
+	p := entry.packets[0]
+	entry.packets = entry.packets[1:]
+	if len(entry.packets) == 0 {
+		entry.timer.Stop()
+		delete(h.queue, string(connID))
 	}
 	return p
 }

zero_rtt_queue_test.go

@@ -2,6 +2,7 @@ package quic
 
 import (
 	"encoding/binary"
+	"time"
 
 	"github.com/lucas-clemente/quic-go/internal/protocol"
 
@@ -85,4 +86,12 @@ var _ = Describe("0-RTT queue", func() {
 		// The queue should now be empty.
 		Expect(q.Dequeue(connID)).To(BeNil())
 	})
+
+	It("deletes packets if they aren't dequeued after a short while", func() {
+		connID := protocol.ConnectionID{0xde, 0xad, 0xbe, 0xef}
+		p := &receivedPacket{data: []byte("foobar")}
+		q.Enqueue(connID, p)
+		time.Sleep(protocol.Max0RTTQueueingDuration * 3 / 2)
+		Expect(q.Dequeue(connID)).To(BeNil())
+	})
 })