Update logging

perf(relay): scale packet workers and queue depth for throughput

relay/relay.go

@@ -9,6 +9,7 @@ import (
 	"io"
 	"net"
 	"net/http"
+	"runtime"
 	"sync"
 	"time"
 
@@ -118,6 +119,13 @@ type Packet struct {
 	n          int
 }
 
+// holePunchRateLimitEntry tracks hole punch message counts within a sliding 1-second window.
+type holePunchRateLimitEntry struct {
+	mu          sync.Mutex
+	count       int
+	windowStart time.Time
+}
+
 // WireGuard message types
 const (
 	WireGuardMessageTypeHandshakeInitiation = 1
@@ -153,6 +161,11 @@ type UDPProxyServer struct {
 	// Communication pattern tracking for rebuilding sessions
 	// Key format: "clientIP:clientPort-destIP:destPort"
 	commPatterns sync.Map
+	// Rate limiter for encrypted hole punch messages, keyed by "ip:port"
+	holePunchRateLimiter sync.Map
+	// Cache for resolved UDP addresses to avoid per-packet DNS lookups
+	// Key: "ip:port" string, Value: *net.UDPAddr
+	addrCache sync.Map
 	// ReachableAt is the URL where this server can be reached
 	ReachableAt string
 }
@@ -164,7 +177,7 @@ func NewUDPProxyServer(parentCtx context.Context, addr, serverURL string, privat
 		addr:        addr,
 		serverURL:   serverURL,
 		privateKey:  privateKey,
-		packetChan:  make(chan Packet, 1000),
+		packetChan:  make(chan Packet, 50000), // Increased from 1000 to handle high throughput
 		ReachableAt: reachableAt,
 		ctx:         ctx,
 		cancel:      cancel,
@@ -189,8 +202,13 @@ func (s *UDPProxyServer) Start() error {
 	s.conn = conn
 	logger.Info("UDP server listening on %s", s.addr)
 
-	// Start a fixed number of worker goroutines.
+	// Start worker goroutines based on CPU cores for better parallelism
-	workerCount := 10 // TODO: Make this configurable or pick it better!
+	// At high throughput (160+ Mbps), we need many workers to avoid bottlenecks
+	workerCount := runtime.NumCPU() * 10
+	if workerCount < 20 {
+		workerCount = 20 // Minimum 20 workers
+	}
+	logger.Info("Starting %d packet workers (CPUs: %d)", workerCount, runtime.NumCPU())
 	for i := 0; i < workerCount; i++ {
 		go s.packetWorker()
 	}
@@ -210,6 +228,9 @@ func (s *UDPProxyServer) Start() error {
 	// Start the communication pattern cleanup routine
 	go s.cleanupIdleCommunicationPatterns()
 
+	// Start the hole punch rate limiter cleanup routine
+	go s.cleanupHolePunchRateLimiter()
+
 	return nil
 }
 
@@ -272,6 +293,27 @@ func (s *UDPProxyServer) packetWorker() {
 			// Process as a WireGuard packet.
 			s.handleWireGuardPacket(packet.data, packet.remoteAddr)
 		} else {
+			// Rate limit: allow at most 2 hole punch messages per IP:Port per second
+			rateLimitKey := packet.remoteAddr.String()
+			entryVal, _ := s.holePunchRateLimiter.LoadOrStore(rateLimitKey, &holePunchRateLimitEntry{
+				windowStart: time.Now(),
+			})
+			rlEntry := entryVal.(*holePunchRateLimitEntry)
+			rlEntry.mu.Lock()
+			now := time.Now()
+			if now.Sub(rlEntry.windowStart) >= time.Second {
+				rlEntry.count = 0
+				rlEntry.windowStart = now
+			}
+			rlEntry.count++
+			allowed := rlEntry.count <= 2
+			rlEntry.mu.Unlock()
+			if !allowed {
+				// logger.Debug("Rate limiting hole punch message from %s", rateLimitKey)
+				bufferPool.Put(packet.data[:1500])
+				continue
+			}
+
 			// Process as an encrypted hole punch message
 			var encMsg EncryptedHolePunchMessage
 			if err := json.Unmarshal(packet.data, &encMsg); err != nil {
@@ -291,7 +333,7 @@ func (s *UDPProxyServer) packetWorker() {
 			// This appears to be an encrypted message
 			decryptedData, err := s.decryptMessage(encMsg)
 			if err != nil {
-				logger.Error("Failed to decrypt message: %v", err)
+				// logger.Error("Failed to decrypt message: %v", err)
 				// Return the buffer to the pool for reuse and continue with next packet
 				bufferPool.Put(packet.data[:1500])
 				continue
@@ -416,6 +458,43 @@ func extractWireGuardIndices(packet []byte) (uint32, uint32, bool) {
 	return 0, 0, false
 }
 
+// cachedAddr holds a resolved UDP address with TTL
+type cachedAddr struct {
+	addr      *net.UDPAddr
+	expiresAt time.Time
+}
+
+// addrCacheTTL is how long resolved addresses are cached before re-resolving
+const addrCacheTTL = 5 * time.Minute
+
+// getCachedAddr returns a cached UDP address or resolves and caches it.
+// This avoids per-packet DNS lookups which are a major throughput bottleneck.
+func (s *UDPProxyServer) getCachedAddr(ip string, port int) (*net.UDPAddr, error) {
+	key := fmt.Sprintf("%s:%d", ip, port)
+
+	// Check cache first
+	if cached, ok := s.addrCache.Load(key); ok {
+		entry := cached.(*cachedAddr)
+		if time.Now().Before(entry.expiresAt) {
+			return entry.addr, nil
+		}
+		// Cache expired, delete and re-resolve
+		s.addrCache.Delete(key)
+	}
+
+	// Resolve and cache
+	addr, err := net.ResolveUDPAddr("udp", key)
+	if err != nil {
+		return nil, err
+	}
+
+	s.addrCache.Store(key, &cachedAddr{
+		addr:      addr,
+		expiresAt: time.Now().Add(addrCacheTTL),
+	})
+	return addr, nil
+}
+
 // Updated to handle multi-peer WireGuard communication
 func (s *UDPProxyServer) handleWireGuardPacket(packet []byte, remoteAddr *net.UDPAddr) {
 	if len(packet) == 0 {
@@ -450,7 +529,7 @@ func (s *UDPProxyServer) handleWireGuardPacket(packet []byte, remoteAddr *net.UD
 		logger.Debug("Forwarding handshake initiation from %s (sender index: %d) to peers %v", remoteAddr, senderIndex, proxyMapping.Destinations)
 
 		for _, dest := range proxyMapping.Destinations {
-			destAddr, err := net.ResolveUDPAddr("udp", fmt.Sprintf("%s:%d", dest.DestinationIP, dest.DestinationPort))
+			destAddr, err := s.getCachedAddr(dest.DestinationIP, dest.DestinationPort)
 			if err != nil {
 				logger.Error("Failed to resolve destination address: %v", err)
 				continue
@@ -486,7 +565,7 @@ func (s *UDPProxyServer) handleWireGuardPacket(packet []byte, remoteAddr *net.UD
 
 		// Forward the response to the original sender
 		for _, dest := range proxyMapping.Destinations {
-			destAddr, err := net.ResolveUDPAddr("udp", fmt.Sprintf("%s:%d", dest.DestinationIP, dest.DestinationPort))
+			destAddr, err := s.getCachedAddr(dest.DestinationIP, dest.DestinationPort)
 			if err != nil {
 				logger.Error("Failed to resolve destination address: %v", err)
 				continue
@@ -543,7 +622,7 @@ func (s *UDPProxyServer) handleWireGuardPacket(packet []byte, remoteAddr *net.UD
 			// No known session, fall back to forwarding to all peers
 			logger.Debug("No session found for receiver index %d, forwarding to all destinations", receiverIndex)
 			for _, dest := range proxyMapping.Destinations {
-				destAddr, err := net.ResolveUDPAddr("udp", fmt.Sprintf("%s:%d", dest.DestinationIP, dest.DestinationPort))
+				destAddr, err := s.getCachedAddr(dest.DestinationIP, dest.DestinationPort)
 				if err != nil {
 					logger.Error("Failed to resolve destination address: %v", err)
 					continue
@@ -571,7 +650,7 @@ func (s *UDPProxyServer) handleWireGuardPacket(packet []byte, remoteAddr *net.UD
 
 		// Forward to all peers
 		for _, dest := range proxyMapping.Destinations {
-			destAddr, err := net.ResolveUDPAddr("udp", fmt.Sprintf("%s:%d", dest.DestinationIP, dest.DestinationPort))
+			destAddr, err := s.getCachedAddr(dest.DestinationIP, dest.DestinationPort)
 			if err != nil {
 				logger.Error("Failed to resolve destination address: %v", err)
 				continue
@@ -1030,6 +1109,30 @@ func (s *UDPProxyServer) tryRebuildSession(pattern *CommunicationPattern) {
 }
 
 // cleanupIdleCommunicationPatterns periodically removes idle communication patterns
+// cleanupHolePunchRateLimiter periodically evicts stale rate limit entries to prevent unbounded growth.
+func (s *UDPProxyServer) cleanupHolePunchRateLimiter() {
+	ticker := time.NewTicker(30 * time.Second)
+	defer ticker.Stop()
+	for {
+		select {
+		case <-ticker.C:
+			now := time.Now()
+			s.holePunchRateLimiter.Range(func(key, value interface{}) bool {
+				rlEntry := value.(*holePunchRateLimitEntry)
+				rlEntry.mu.Lock()
+				stale := now.Sub(rlEntry.windowStart) > 10*time.Second
+				rlEntry.mu.Unlock()
+				if stale {
+					s.holePunchRateLimiter.Delete(key)
+				}
+				return true
+			})
+		case <-s.ctx.Done():
+			return
+		}
+	}
+}
+
 func (s *UDPProxyServer) cleanupIdleCommunicationPatterns() {
 	ticker := time.NewTicker(10 * time.Minute)
 	defer ticker.Stop()