use wg tun library; batching & locking improvements

outside.go

@@ -102,7 +102,7 @@ func (f *Interface) readOutsidePackets(via ViaSender, out []byte, packet []byte,
 					relay:     relay,
 					IsRelayed: true,
 				}
-				f.readOutsidePackets(via, out[:0], signedPayload, h, fwPacket, lhf, nb, q, localCache)
+				f.readOutsidePackets(via, out[:virtioNetHdrLen], signedPayload, h, fwPacket, lhf, nb, q, localCache)
 				return
 			case ForwardingType:
 				// Find the target HostInfo relay object
@@ -145,7 +145,7 @@ func (f *Interface) readOutsidePackets(via ViaSender, out []byte, packet []byte,
 		}
 
 		//TODO: assert via is not relayed
-		lhf.HandleRequest(via.UdpAddr, hostinfo.vpnAddrs, d, f)
+		lhf.HandleRequest(via.UdpAddr, hostinfo.vpnAddrs, d[virtioNetHdrLen:], f)
 
 		// Fallthrough to the bottom to record incoming traffic
 
@@ -167,7 +167,7 @@ func (f *Interface) readOutsidePackets(via ViaSender, out []byte, packet []byte,
 			// This testRequest might be from TryPromoteBest, so we should roam
 			// to the new IP address before responding
 			f.handleHostRoaming(hostinfo, via)
-			f.send(header.Test, header.TestReply, ci, hostinfo, d, nb, out)
+			f.send(header.Test, header.TestReply, ci, hostinfo, d[virtioNetHdrLen:], nb, out)
 		}
 
 		// Fallthrough to the bottom to record incoming traffic
@@ -210,7 +210,7 @@ func (f *Interface) readOutsidePackets(via ViaSender, out []byte, packet []byte,
 			return
 		}
 
-		f.relayManager.HandleControlMsg(hostinfo, d, f)
+		f.relayManager.HandleControlMsg(hostinfo, d[virtioNetHdrLen:], f)
 
 	default:
 		f.messageMetrics.Rx(h.Type, h.Subtype, 1)
@@ -481,9 +481,11 @@ func (f *Interface) decryptToTun(hostinfo *HostInfo, messageCounter uint64, out
 		return false
 	}
 
-	err = newPacket(out, true, fwPacket)
+	packetData := out[virtioNetHdrLen:]
+
+	err = newPacket(packetData, true, fwPacket)
 	if err != nil {
-		hostinfo.logger(f.l).WithError(err).WithField("packet", out).
+		hostinfo.logger(f.l).WithError(err).WithField("packet", packetData).
 			Warnf("Error while validating inbound packet")
 		return false
 	}
@@ -498,7 +500,7 @@ func (f *Interface) decryptToTun(hostinfo *HostInfo, messageCounter uint64, out
 	if dropReason != nil {
 		// NOTE: We give `packet` as the `out` here since we already decrypted from it and we don't need it anymore
 		// This gives us a buffer to build the reject packet in
-		f.rejectOutside(out, hostinfo.ConnectionState, hostinfo, nb, packet, q)
+		f.rejectOutside(packetData, hostinfo.ConnectionState, hostinfo, nb, packet, q)
 		if f.l.Level >= logrus.DebugLevel {
 			hostinfo.logger(f.l).WithField("fwPacket", fwPacket).
 				WithField("reason", dropReason).
@@ -562,3 +564,108 @@ func (f *Interface) handleRecvError(addr netip.AddrPort, h *header.H) {
 	// We also delete it from pending hostmap to allow for fast reconnect.
 	f.handshakeManager.DeleteHostInfo(hostinfo)
 }
+
+// readOutsidePacketsBatch processes multiple packets received from UDP in a batch
+// and writes all successfully decrypted packets to TUN in a single operation
+func (f *Interface) readOutsidePacketsBatch(addrs []netip.AddrPort, payloads [][]byte, count int, outs [][]byte, nb []byte, q int, h *header.H, fwPacket *firewall.Packet, lhf *LightHouseHandler, localCache firewall.ConntrackCache) {
+	// Pre-allocate slice for accumulating successful decryptions
+	tunPackets := make([][]byte, 0, count)
+
+	for i := 0; i < count; i++ {
+		payload := payloads[i]
+		addr := addrs[i]
+		out := outs[i]
+
+		// Parse header
+		err := h.Parse(payload)
+		if err != nil {
+			if len(payload) > 1 {
+				f.l.WithField("packet", payload).Infof("Error while parsing inbound packet from %s: %s", addr, err)
+			}
+			continue
+		}
+
+		if addr.IsValid() {
+			if f.myVpnNetworksTable.Contains(addr.Addr()) {
+				if f.l.Level >= logrus.DebugLevel {
+					f.l.WithField("udpAddr", addr).Debug("Refusing to process double encrypted packet")
+				}
+				continue
+			}
+		}
+
+		var hostinfo *HostInfo
+		if h.Type == header.Message && h.Subtype == header.MessageRelay {
+			hostinfo = f.hostMap.QueryRelayIndex(h.RemoteIndex)
+		} else {
+			hostinfo = f.hostMap.QueryIndex(h.RemoteIndex)
+		}
+
+		var ci *ConnectionState
+		if hostinfo != nil {
+			ci = hostinfo.ConnectionState
+		}
+
+		switch h.Type {
+		case header.Message:
+			if !f.handleEncrypted(ci, ViaSender{UdpAddr: addr}, h) {
+				continue
+			}
+
+			switch h.Subtype {
+			case header.MessageNone:
+				// Decrypt packet
+				out, err = hostinfo.ConnectionState.dKey.DecryptDanger(out, payload[:header.Len], payload[header.Len:], h.MessageCounter, nb)
+				if err != nil {
+					hostinfo.logger(f.l).WithError(err).Error("Failed to decrypt packet")
+					continue
+				}
+
+				packetData := out[virtioNetHdrLen:]
+
+				err = newPacket(packetData, true, fwPacket)
+				if err != nil {
+					hostinfo.logger(f.l).WithError(err).WithField("packet", packetData).Warnf("Error while validating inbound packet")
+					continue
+				}
+
+				if !hostinfo.ConnectionState.window.Update(f.l, h.MessageCounter) {
+					hostinfo.logger(f.l).WithField("fwPacket", fwPacket).Debugln("dropping out of window packet")
+					continue
+				}
+
+				dropReason := f.firewall.Drop(*fwPacket, true, hostinfo, f.pki.GetCAPool(), localCache)
+				if dropReason != nil {
+					f.rejectOutside(packetData, hostinfo.ConnectionState, hostinfo, nb, payload, q)
+					if f.l.Level >= logrus.DebugLevel {
+						hostinfo.logger(f.l).WithField("fwPacket", fwPacket).WithField("reason", dropReason).Debugln("dropping inbound packet")
+					}
+					continue
+				}
+
+				f.connectionManager.In(hostinfo)
+				// Add to batch for TUN write
+				tunPackets = append(tunPackets, out)
+
+			case header.MessageRelay:
+				// Skip relay packets in batch mode for now (less common path)
+				f.readOutsidePackets(ViaSender{UdpAddr: addr}, out[:virtioNetHdrLen], payload, h, fwPacket, lhf, nb, q, localCache)
+
+			default:
+				hostinfo.logger(f.l).Debugf("unexpected message subtype %d", h.Subtype)
+			}
+
+		default:
+			// Handle non-Message types using single-packet path
+			f.readOutsidePackets(ViaSender{UdpAddr: addr}, out[:virtioNetHdrLen], payload, h, fwPacket, lhf, nb, q, localCache)
+		}
+	}
+
+	if len(tunPackets) > 0 {
+		n, err := f.readers[q].WriteBatch(tunPackets, virtioNetHdrLen)
+		if err != nil {
+			f.l.WithError(err).WithField("sent", n).WithField("total", len(tunPackets)).Error("Failed to batch write to tun")
+		}
+
+	}
+}