DNS peers handled the same as boot nodes (#4178)

* DNS peers handled the same as boot nodes
* make sure that non bonded peers can be used as initial peers
* try to connect to DNS nodes

Signed-off-by: Stefan <stefan.pingel@consensys.net>

Co-authored-by: Justin Florentine <justin+github@florentine.us>

besu/src/main/java/org/hyperledger/besu/cli/options/unstable/NetworkingOptions.java

@@ -85,7 +85,7 @@ public class NetworkingOptions implements CLIOptions<NetworkingConfiguration> {
 
   @Override
   public NetworkingConfiguration toDomainObject() {
-    NetworkingConfiguration config = NetworkingConfiguration.create();
+    final NetworkingConfiguration config = NetworkingConfiguration.create();
     config.setCheckMaintainedConnectionsFrequency(checkMaintainedConnectionsFrequencySec);
     config.setInitiateConnectionsFrequency(initiateConnectionsFrequencySec);
     config.setDnsDiscoveryServerOverride(dnsDiscoveryServerOverride);
@@ -95,7 +95,7 @@ public class NetworkingOptions implements CLIOptions<NetworkingConfiguration> {
 
   @Override
   public List<String> getCLIOptions() {
-    List<String> retval =
+    final List<String> retval =
         Arrays.asList(
             CHECK_MAINTAINED_CONNECTIONS_FREQUENCY_FLAG,
             OptionParser.format(checkMaintainedConnectionsFrequencySec),

ethereum/eth/src/main/java/org/hyperledger/besu/ethereum/eth/manager/EthProtocolManager.java

@@ -72,6 +72,7 @@ public class EthProtocolManager implements ProtocolManager, MinedBlockObserver {
   private final BlockBroadcaster blockBroadcaster;
   private final List<PeerValidator> peerValidators;
   private final Optional<MergePeerFilter> mergePeerFilter;
+  private final int maxMessageSize;
 
   public EthProtocolManager(
       final Blockchain blockchain,
@@ -101,6 +102,8 @@ public class EthProtocolManager implements ProtocolManager, MinedBlockObserver {
     this.ethMessages = ethMessages;
     this.ethContext = ethContext;
 
+    this.maxMessageSize = ethereumWireProtocolConfiguration.getMaxMessageSize();
+
     this.blockBroadcaster = new BlockBroadcaster(ethContext);
 
     supportedCapabilities = calculateCapabilities(fastSyncEnabled);
@@ -278,6 +281,14 @@ public class EthProtocolManager implements ProtocolManager, MinedBlockObserver {
       return;
     }
 
+    if (messageData.getSize() > this.maxMessageSize) {
+      LOG.debug(
+          "Peer {} sent a message with size {}, larger than the max message size {}",
+          ethPeer,
+          messageData.getSize(),
+          this.maxMessageSize);
+    }
+
     // This will handle responses
     ethPeers.dispatchMessage(ethPeer, ethMessage, getSupportedProtocol());
 

ethereum/p2p/src/main/java/org/hyperledger/besu/ethereum/p2p/discovery/PeerDiscoveryAgent.java

@@ -179,6 +179,10 @@ public abstract class PeerDiscoveryAgent {
     }
   }
 
+  public Optional<PeerDiscoveryController> getPeerDiscoveryController() {
+    return controller;
+  }
+
   public void updateNodeRecord() {
     if (!config.isActive()) {
       return;

ethereum/p2p/src/main/java/org/hyperledger/besu/ethereum/p2p/discovery/internal/PeerDiscoveryController.java

@@ -315,7 +315,7 @@ public class PeerDiscoveryController {
             .ifPresent(
                 interaction -> {
                   bondingPeers.invalidate(peer.getId());
-                  addToPeerTable(peer);
+                  addBondedPeerToPeerTable(peer);
                   recursivePeerRefreshState.onBondingComplete(peer);
                 });
         break;
@@ -369,16 +369,11 @@ public class PeerDiscoveryController {
         .collect(Collectors.toList());
   }
 
-  private boolean addToPeerTable(final DiscoveryPeer peer) {
+  private boolean addBondedPeerToPeerTable(final DiscoveryPeer peer) {
     if (!peerPermissions.isAllowedInPeerTable(peer)) {
       return false;
     }
 
-    final PeerTable.AddResult result = peerTable.tryAdd(peer);
-    if (result.getOutcome() == PeerTable.AddResult.AddOutcome.SELF) {
-      return false;
-    }
-
     // Reset the last seen timestamp.
     final long now = System.currentTimeMillis();
     if (peer.getFirstDiscovered() == 0) {
@@ -391,6 +386,16 @@ public class PeerDiscoveryController {
       notifyPeerBonded(peer, now);
     }
 
+    return addToPeerTable(peer);
+  }
+
+  public boolean addToPeerTable(final DiscoveryPeer peer) {
+    final PeerTable.AddResult result = peerTable.tryAdd(peer);
+
+    if (result.getOutcome() == PeerTable.AddResult.AddOutcome.SELF) {
+      return false;
+    }
+
     if (result.getOutcome() == PeerTable.AddResult.AddOutcome.ALREADY_EXISTED) {
       // Bump peer.
       peerTable.tryEvict(peer);
@@ -584,7 +589,7 @@ public class PeerDiscoveryController {
     // 16 + 4 + 4 + 64 = 88 bytes
     // 88 * 13 = 1144 bytes
     // To fit under 1280 bytes, we must return just 13 peers maximum.
-    final List<DiscoveryPeer> peers = peerTable.nearestPeers(packetData.getTarget(), 13);
+    final List<DiscoveryPeer> peers = peerTable.nearestBondedPeers(packetData.getTarget(), 13);
     final PacketData data = NeighborsPacketData.create(peers);
     sendPacket(sender, PacketType.NEIGHBORS, data);
   }
@@ -636,7 +641,7 @@ public class PeerDiscoveryController {
         peerTable.get(peer).filter(known -> known.discoveryEndpointMatches(peer));
     DiscoveryPeer resolvedPeer = maybeKnownPeer.orElse(peer);
     if (maybeKnownPeer.isEmpty()) {
-      DiscoveryPeer bondingPeer = bondingPeers.getIfPresent(peer.getId());
+      final DiscoveryPeer bondingPeer = bondingPeers.getIfPresent(peer.getId());
       if (bondingPeer != null) {
         resolvedPeer = bondingPeer;
       }

ethereum/p2p/src/main/java/org/hyperledger/besu/ethereum/p2p/discovery/internal/PeerRequirement.java

@@ -25,7 +25,7 @@ public interface PeerRequirement {
 
   static PeerRequirement combine(final Collection<PeerRequirement> peerRequirements) {
     return () -> {
-      for (PeerRequirement peerRequirement : peerRequirements) {
+      for (final PeerRequirement peerRequirement : peerRequirements) {
         if (!peerRequirement.hasSufficientPeers()) {
           return false;
         }

ethereum/p2p/src/main/java/org/hyperledger/besu/ethereum/p2p/discovery/internal/PeerTable.java

@@ -182,6 +182,24 @@ public class PeerTable {
     this.idBloom = bf;
   }
 
+  /**
+   * Returns the <code>limit</code> peers (at most) bonded closest to the provided target, based on
+   * the XOR distance between the keccak-256 hash of the ID and the keccak-256 hash of the target.
+   *
+   * @param target The target node ID.
+   * @param limit The amount of results to return.
+   * @return The <code>limit</code> closest peers, at most.
+   */
+  public List<DiscoveryPeer> nearestBondedPeers(final Bytes target, final int limit) {
+    final Bytes keccak256 = Hash.keccak256(target);
+    return streamAllPeers()
+        .filter(p -> p.getStatus() == PeerDiscoveryStatus.BONDED)
+        .sorted(
+            comparingInt((peer) -> PeerDistanceCalculator.distance(peer.keccak256(), keccak256)))
+        .limit(limit)
+        .collect(toList());
+  }
+
   /**
    * Returns the <code>limit</code> peers (at most) closest to the provided target, based on the XOR
    * distance between the keccak-256 hash of the ID and the keccak-256 hash of the target.
@@ -193,7 +211,6 @@ public class PeerTable {
   public List<DiscoveryPeer> nearestPeers(final Bytes target, final int limit) {
     final Bytes keccak256 = Hash.keccak256(target);
     return streamAllPeers()
-        .filter(p -> p.getStatus() == PeerDiscoveryStatus.BONDED)
         .sorted(
             comparingInt((peer) -> PeerDistanceCalculator.distance(peer.keccak256(), keccak256)))
         .limit(limit)

ethereum/p2p/src/main/java/org/hyperledger/besu/ethereum/p2p/discovery/internal/PingPacketData.java

@@ -98,9 +98,9 @@ public class PingPacketData implements PacketData {
     if (!in.isEndOfCurrentList()) {
       try {
         enrSeq = UInt64.valueOf(in.readBigIntegerScalar());
-        LOG.debug("read PING enr as long scalar");
+        LOG.trace("read PING enr as long scalar");
       } catch (MalformedRLPInputException malformed) {
-        LOG.debug("failed to read PING enr as scalar, trying to read bytes instead");
+        LOG.trace("failed to read PING enr as scalar, trying to read bytes instead");
         enrSeq = UInt64.fromBytes(in.readBytes());
       }
     }

ethereum/p2p/src/main/java/org/hyperledger/besu/ethereum/p2p/discovery/internal/PongPacketData.java

@@ -63,9 +63,9 @@ public class PongPacketData implements PacketData {
     if (!in.isEndOfCurrentList()) {
       try {
         enrSeq = UInt64.valueOf(in.readBigIntegerScalar());
-        LOG.debug("read PONG enr from scalar");
+        LOG.trace("read PONG enr from scalar");
-      } catch (MalformedRLPInputException malformed) {
+      } catch (final MalformedRLPInputException malformed) {
-        LOG.debug("failed to read PONG enr from scalar, trying as byte array");
+        LOG.trace("failed to read PONG enr from scalar, trying as byte array");
         enrSeq = UInt64.fromBytes(in.readBytes());
       }
     }

ethereum/p2p/src/main/java/org/hyperledger/besu/ethereum/p2p/discovery/internal/RecursivePeerRefreshState.java

@@ -93,6 +93,7 @@ public class RecursivePeerRefreshState {
   }
 
   private void addInitialPeers(final List<DiscoveryPeer> initialPeers) {
+    LOG.debug("INITIAL PEERS: {}", initialPeers);
     this.initialPeers = initialPeers;
     for (final DiscoveryPeer peer : initialPeers) {
       final MetadataPeer iterationParticipant =

ethereum/p2p/src/main/java/org/hyperledger/besu/ethereum/p2p/network/DefaultP2PNetwork.java

@@ -25,6 +25,7 @@ import org.hyperledger.besu.ethereum.p2p.discovery.PeerDiscoveryAgent;
 import org.hyperledger.besu.ethereum.p2p.discovery.PeerDiscoveryEvent.PeerBondedEvent;
 import org.hyperledger.besu.ethereum.p2p.discovery.PeerDiscoveryStatus;
 import org.hyperledger.besu.ethereum.p2p.discovery.VertxPeerDiscoveryAgent;
+import org.hyperledger.besu.ethereum.p2p.discovery.internal.PeerDiscoveryController;
 import org.hyperledger.besu.ethereum.p2p.peers.DefaultPeerPrivileges;
 import org.hyperledger.besu.ethereum.p2p.peers.EnodeURLImpl;
 import org.hyperledger.besu.ethereum.p2p.peers.LocalNode;
@@ -56,7 +57,6 @@ import java.time.Duration;
 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.Collection;
-import java.util.Collections;
 import java.util.Comparator;
 import java.util.List;
 import java.util.Optional;
@@ -67,7 +67,6 @@ import java.util.concurrent.Executors;
 import java.util.concurrent.ScheduledExecutorService;
 import java.util.concurrent.TimeUnit;
 import java.util.concurrent.atomic.AtomicBoolean;
-import java.util.concurrent.atomic.AtomicReference;
 import java.util.function.Consumer;
 import java.util.function.Supplier;
 import java.util.stream.Collectors;
@@ -149,8 +148,6 @@ public class DefaultP2PNetwork implements P2PNetwork {
   private final Duration shutdownTimeout = Duration.ofMinutes(1);
   private DNSDaemon dnsDaemon;
 
-  @VisibleForTesting final AtomicReference<List<DiscoveryPeer>> dnsPeers = new AtomicReference<>();
-
   /**
    * Creates a peer networking service for production purposes.
    *
@@ -215,6 +212,8 @@ public class DefaultP2PNetwork implements P2PNetwork {
     Optional.ofNullable(config.getDiscovery().getDNSDiscoveryURL())
         .ifPresent(
             disco -> {
+              // These lists are updated every 12h
+              // We retrieve the list every 30 minutes (1800000 msec)
               LOG.info("Starting DNS discovery with URL {}", disco);
               config
                   .getDnsDiscoveryServerOverride()
@@ -228,7 +227,7 @@ public class DefaultP2PNetwork implements P2PNetwork {
                       disco,
                       createDaemonListener(),
                       0L,
-                      60000L,
+                      1800000L,
                       config.getDnsDiscoveryServerOverride().orElse(null));
               dnsDaemon.start();
             });
@@ -347,11 +346,16 @@ public class DefaultP2PNetwork implements P2PNetwork {
                 .build();
         final DiscoveryPeer peer = DiscoveryPeer.fromEnode(enodeURL);
         peers.add(peer);
-        rlpxAgent.connect(peer);
       }
-      // only replace dnsPeers if the lookup was successful:
       if (!peers.isEmpty()) {
-        dnsPeers.set(peers);
+        final Optional<PeerDiscoveryController> peerDiscoveryController =
+            peerDiscoveryAgent.getPeerDiscoveryController();
+        if (peerDiscoveryController.isPresent()) {
+          final PeerDiscoveryController controller = peerDiscoveryController.get();
+          LOG.debug("Adding {} DNS peers to PeerTable", peers.size());
+          peers.forEach(controller::addToPeerTable);
+          peers.forEach(rlpxAgent::connect);
+        }
       }
     };
   }
@@ -383,11 +387,6 @@ public class DefaultP2PNetwork implements P2PNetwork {
 
   @Override
   public Stream<DiscoveryPeer> streamDiscoveredPeers() {
-    final List<DiscoveryPeer> peers = dnsPeers.get();
-    if (peers != null) {
-      Collections.shuffle(peers);
-      return Stream.concat(peerDiscoveryAgent.streamDiscoveredPeers(), peers.stream());
-    }
     return peerDiscoveryAgent.streamDiscoveredPeers();
   }
 

ethereum/p2p/src/main/java/org/hyperledger/besu/ethereum/p2p/rlpx/RlpxAgent.java

@@ -222,8 +222,7 @@ public class RlpxAgent {
     // Check peer is valid
     final EnodeURL enode = peer.getEnodeURL();
     if (!enode.isListening()) {
-      final String errorMsg =
+      final String errorMsg = "Attempt to connect to peer with no listening port: " + enode;
-          "Attempt to connect to peer with no listening port: " + enode.toString();
       LOG.warn(errorMsg);
       return CompletableFuture.failedFuture((new IllegalArgumentException(errorMsg)));
     }

ethereum/p2p/src/main/java/org/hyperledger/besu/ethereum/p2p/rlpx/connections/netty/ApiHandler.java

@@ -63,7 +63,7 @@ final class ApiHandler extends SimpleChannelInboundHandler<MessageData> {
     if (demultiplexed.getCapability() == null) {
       switch (message.getCode()) {
         case WireMessageCodes.PING:
-          LOG.debug("Received Wire PING");
+          LOG.trace("Received Wire PING");
           try {
             connection.send(null, PongMessage.get());
           } catch (final PeerConnection.PeerNotConnected peerNotConnected) {
@@ -71,7 +71,7 @@ final class ApiHandler extends SimpleChannelInboundHandler<MessageData> {
           }
           break;
         case WireMessageCodes.PONG:
-          LOG.debug("Received Wire PONG");
+          LOG.trace("Received Wire PONG");
           waitingForPong.set(false);
           break;
         case WireMessageCodes.DISCONNECT:

ethereum/p2p/src/test/java/org/hyperledger/besu/ethereum/p2p/network/DefaultP2PNetworkTest.java

@@ -53,7 +53,6 @@ import org.hyperledger.besu.nat.NatService;
 import org.hyperledger.besu.nat.core.domain.NetworkProtocol;
 import org.hyperledger.besu.nat.upnp.UpnpNatManager;
 
-import java.net.InetAddress;
 import java.util.ArrayList;
 import java.util.Collections;
 import java.util.List;
@@ -65,8 +64,6 @@ import java.util.stream.Stream;
 import org.apache.tuweni.bytes.Bytes;
 import org.apache.tuweni.bytes.Bytes32;
 import org.apache.tuweni.crypto.SECP256K1;
-import org.apache.tuweni.devp2p.EthereumNodeRecord;
-import org.apache.tuweni.discovery.DNSDaemonListener;
 import org.assertj.core.api.Assertions;
 import org.junit.Before;
 import org.junit.Test;
@@ -410,35 +407,6 @@ public final class DefaultP2PNetworkTest {
     verify(dnsConfig, times(2)).getDnsDiscoveryServerOverride();
   }
 
-  @Test
-  public void shouldNotDropDnsHostsOnEmptyLookup() {
-    DefaultP2PNetwork network = network();
-    DNSDaemonListener listenerUnderTest = network.createDaemonListener();
-
-    // assert no entries prior to lookup
-    assertThat(network.dnsPeers.get()).isNull();
-
-    // simulate successful lookup of 1 peer
-    listenerUnderTest.newRecords(
-        1,
-        List.of(
-            EthereumNodeRecord.create(
-                SECP256K1.KeyPair.fromSecretKey(mockKey),
-                1L,
-                null,
-                null,
-                InetAddress.getLoopbackAddress(),
-                30303,
-                30303)));
-    assertThat(network.dnsPeers.get()).isNotEmpty();
-    assertThat(network.dnsPeers.get().size()).isEqualTo(1);
-
-    // simulate failed lookup empty list
-    listenerUnderTest.newRecords(2, Collections.emptyList());
-    assertThat(network.dnsPeers.get()).isNotEmpty();
-    assertThat(network.dnsPeers.get().size()).isEqualTo(1);
-  }
-
   private DefaultP2PNetwork network() {
     return (DefaultP2PNetwork) builder().build();
   }

ethereum/p2p/src/test/java/org/hyperledger/besu/ethereum/p2p/rlpx/connections/netty/DeFramerTest.java

@@ -167,26 +167,26 @@ public class DeFramerTest {
 
   @Test
   public void decode_handlesHello() throws ExecutionException, InterruptedException {
-    ChannelFuture future = NettyMocks.channelFuture(false);
+    final ChannelFuture future = NettyMocks.channelFuture(false);
     when(channel.closeFuture()).thenReturn(future);
 
     final Peer peer = createRemotePeer();
     final PeerInfo remotePeerInfo = createPeerInfo(peer);
 
-    HelloMessage helloMessage = HelloMessage.create(remotePeerInfo);
+    final HelloMessage helloMessage = HelloMessage.create(remotePeerInfo);
-    ByteBuf data = Unpooled.wrappedBuffer(helloMessage.getData().toArray());
+    final ByteBuf data = Unpooled.wrappedBuffer(helloMessage.getData().toArray());
     when(framer.deframe(eq(data)))
         .thenReturn(new RawMessage(helloMessage.getCode(), helloMessage.getData()))
         .thenReturn(null);
-    List<Object> out = new ArrayList<>();
+    final List<Object> out = new ArrayList<>();
     deFramer.decode(ctx, data, out);
 
     assertThat(connectFuture).isDone();
     assertThat(connectFuture).isNotCompletedExceptionally();
-    PeerConnection peerConnection = connectFuture.get();
+    final PeerConnection peerConnection = connectFuture.get();
     assertThat(peerConnection.getPeerInfo()).isEqualTo(remotePeerInfo);
 
-    EnodeURL expectedEnode =
+    final EnodeURL expectedEnode =
         EnodeURLImpl.builder()
             .configureFromEnode(peer.getEnodeURL())
             // Discovery information is not available from peer info
@@ -199,8 +199,8 @@ public class DeFramerTest {
     verify(pipeline, times(1)).addLast(any());
 
     // Next message should be pushed out
-    PingMessage nextMessage = PingMessage.get();
+    final PingMessage nextMessage = PingMessage.get();
-    ByteBuf nextData = Unpooled.wrappedBuffer(nextMessage.getData().toArray());
+    final ByteBuf nextData = Unpooled.wrappedBuffer(nextMessage.getData().toArray());
     when(framer.deframe(eq(nextData)))
         .thenReturn(new RawMessage(nextMessage.getCode(), nextMessage.getData()))
         .thenReturn(null);
@@ -212,7 +212,7 @@ public class DeFramerTest {
   @Test
   public void decode_handlesHelloFromPeerWithAdvertisedPortOf0()
       throws ExecutionException, InterruptedException {
-    ChannelFuture future = NettyMocks.channelFuture(false);
+    final ChannelFuture future = NettyMocks.channelFuture(false);
     when(channel.closeFuture()).thenReturn(future);
 
     final Peer peer = createRemotePeer();
@@ -220,17 +220,17 @@ public class DeFramerTest {
         new PeerInfo(p2pVersion, clientId, capabilities, 0, peer.getId());
     final DeFramer deFramer = createDeFramer(null);
 
-    HelloMessage helloMessage = HelloMessage.create(remotePeerInfo);
+    final HelloMessage helloMessage = HelloMessage.create(remotePeerInfo);
-    ByteBuf data = Unpooled.wrappedBuffer(helloMessage.getData().toArray());
+    final ByteBuf data = Unpooled.wrappedBuffer(helloMessage.getData().toArray());
     when(framer.deframe(eq(data)))
         .thenReturn(new RawMessage(helloMessage.getCode(), helloMessage.getData()))
         .thenReturn(null);
-    List<Object> out = new ArrayList<>();
+    final List<Object> out = new ArrayList<>();
     deFramer.decode(ctx, data, out);
 
     assertThat(connectFuture).isDone();
     assertThat(connectFuture).isNotCompletedExceptionally();
-    PeerConnection peerConnection = connectFuture.get();
+    final PeerConnection peerConnection = connectFuture.get();
     assertThat(peerConnection.getPeerInfo()).isEqualTo(remotePeerInfo);
     assertThat(out).isEmpty();
 
@@ -249,8 +249,8 @@ public class DeFramerTest {
     verify(pipeline, times(1)).addLast(any());
 
     // Next message should be pushed out
-    PingMessage nextMessage = PingMessage.get();
+    final PingMessage nextMessage = PingMessage.get();
-    ByteBuf nextData = Unpooled.wrappedBuffer(nextMessage.getData().toArray());
+    final ByteBuf nextData = Unpooled.wrappedBuffer(nextMessage.getData().toArray());
     when(framer.deframe(eq(nextData)))
         .thenReturn(new RawMessage(nextMessage.getCode(), nextMessage.getData()))
         .thenReturn(null);
@@ -261,7 +261,7 @@ public class DeFramerTest {
 
   @Test
   public void decode_handlesUnexpectedPeerId() {
-    ChannelFuture future = NettyMocks.channelFuture(false);
+    final ChannelFuture future = NettyMocks.channelFuture(false);
     when(channel.closeFuture()).thenReturn(future);
 
     final Peer peer = createRemotePeer();
@@ -275,12 +275,12 @@ public class DeFramerTest {
             mismatchedId);
     final DeFramer deFramer = createDeFramer(peer);
 
-    HelloMessage helloMessage = HelloMessage.create(remotePeerInfo);
+    final HelloMessage helloMessage = HelloMessage.create(remotePeerInfo);
-    ByteBuf data = Unpooled.wrappedBuffer(helloMessage.getData().toArray());
+    final ByteBuf data = Unpooled.wrappedBuffer(helloMessage.getData().toArray());
     when(framer.deframe(eq(data)))
         .thenReturn(new RawMessage(helloMessage.getCode(), helloMessage.getData()))
         .thenReturn(null);
-    List<Object> out = new ArrayList<>();
+    final List<Object> out = new ArrayList<>();
     deFramer.decode(ctx, data, out);
 
     assertThat(connectFuture).isDone();
@@ -297,22 +297,22 @@ public class DeFramerTest {
 
   @Test
   public void decode_handlesNoSharedCaps() {
-    ChannelFuture future = NettyMocks.channelFuture(false);
+    final ChannelFuture future = NettyMocks.channelFuture(false);
     when(channel.closeFuture()).thenReturn(future);
 
-    PeerInfo remotePeerInfo =
+    final PeerInfo remotePeerInfo =
         new PeerInfo(
             p2pVersion,
             "bla",
             Arrays.asList(Capability.create("eth", 254)),
             30303,
             Peer.randomId());
-    HelloMessage helloMessage = HelloMessage.create(remotePeerInfo);
+    final HelloMessage helloMessage = HelloMessage.create(remotePeerInfo);
-    ByteBuf data = Unpooled.wrappedBuffer(helloMessage.getData().toArray());
+    final ByteBuf data = Unpooled.wrappedBuffer(helloMessage.getData().toArray());
     when(framer.deframe(eq(data)))
         .thenReturn(new RawMessage(helloMessage.getCode(), helloMessage.getData()))
         .thenReturn(null);
-    List<Object> out = new ArrayList<>();
+    final List<Object> out = new ArrayList<>();
     deFramer.decode(ctx, data, out);
 
     assertThat(connectFuture).isDone();
@@ -326,12 +326,13 @@ public class DeFramerTest {
 
   @Test
   public void decode_shouldHandleImmediateDisconnectMessage() {
-    DisconnectMessage disconnectMessage = DisconnectMessage.create(DisconnectReason.TOO_MANY_PEERS);
+    final DisconnectMessage disconnectMessage =
-    ByteBuf disconnectData = Unpooled.wrappedBuffer(disconnectMessage.getData().toArray());
+        DisconnectMessage.create(DisconnectReason.TOO_MANY_PEERS);
+    final ByteBuf disconnectData = Unpooled.wrappedBuffer(disconnectMessage.getData().toArray());
     when(framer.deframe(eq(disconnectData)))
         .thenReturn(new RawMessage(disconnectMessage.getCode(), disconnectMessage.getData()))
         .thenReturn(null);
-    List<Object> out = new ArrayList<>();
+    final List<Object> out = new ArrayList<>();
     deFramer.decode(ctx, disconnectData, out);
 
     assertThat(connectFuture).isDone();
@@ -347,15 +348,15 @@ public class DeFramerTest {
     final Peer peer = createRemotePeer();
     final PeerInfo remotePeerInfo =
         new PeerInfo(p2pVersion, clientId, capabilities, 0, peer.getId());
-    HelloMessage helloMessage = HelloMessage.create(remotePeerInfo);
+    final HelloMessage helloMessage = HelloMessage.create(remotePeerInfo);
-    ByteBuf data = Unpooled.wrappedBuffer(helloMessage.getData().toArray());
+    final ByteBuf data = Unpooled.wrappedBuffer(helloMessage.getData().toArray());
     when(framer.deframe(any()))
         .thenReturn(new RawMessage(helloMessage.getCode(), helloMessage.getData()))
         .thenReturn(null);
     when(ctx.channel().remoteAddress()).thenReturn(null);
-    ChannelFuture future = NettyMocks.channelFuture(true);
+    final ChannelFuture future = NettyMocks.channelFuture(true);
     when(ctx.writeAndFlush(any())).thenReturn(future);
-    List<Object> out = new ArrayList<>();
+    final List<Object> out = new ArrayList<>();
     deFramer.decode(ctx, data, out);
 
     assertThat(connectFuture).isDone();
@@ -367,22 +368,23 @@ public class DeFramerTest {
 
   @Test
   public void decode_shouldHandleInvalidMessage() {
-    MessageData messageData = PingMessage.get();
+    final MessageData messageData = PingMessage.get();
-    ByteBuf data = Unpooled.wrappedBuffer(messageData.getData().toArray());
+    final ByteBuf data = Unpooled.wrappedBuffer(messageData.getData().toArray());
     when(framer.deframe(eq(data)))
         .thenReturn(new RawMessage(messageData.getCode(), messageData.getData()))
         .thenReturn(null);
-    ChannelFuture future = NettyMocks.channelFuture(true);
+    final ChannelFuture future = NettyMocks.channelFuture(true);
     when(ctx.writeAndFlush(any())).thenReturn(future);
-    List<Object> out = new ArrayList<>();
+    final List<Object> out = new ArrayList<>();
     deFramer.decode(ctx, data, out);
 
-    ArgumentCaptor<Object> outboundMessageArgumentCaptor =
+    final ArgumentCaptor<Object> outboundMessageArgumentCaptor =
         ArgumentCaptor.forClass(OutboundMessage.class);
     verify(ctx, times(1)).writeAndFlush(outboundMessageArgumentCaptor.capture());
-    OutboundMessage outboundMessage = (OutboundMessage) outboundMessageArgumentCaptor.getValue();
+    final OutboundMessage outboundMessage =
+        (OutboundMessage) outboundMessageArgumentCaptor.getValue();
     assertThat(outboundMessage.getCapability()).isNull();
-    MessageData outboundMessageData = outboundMessage.getData();
+    final MessageData outboundMessageData = outboundMessage.getData();
     assertThat(outboundMessageData.getCode()).isEqualTo(WireMessageCodes.DISCONNECT);
     assertThat(DisconnectMessage.readFrom(outboundMessageData).getReason())
         .isEqualTo(DisconnectReason.BREACH_OF_PROTOCOL);