IBFT ensure non-validator does not partake in consensus (#627)

Nodes which are not validators in a network should not inject
IBFT messages to the consensus round, and should not gossip
received messages.

I.e. all events should ensure that they are only handled if
the node is a validator at the current height.
Signed-off-by: Adrian Sutton <adrian.sutton@consensys.net>

consensus/ibft/src/main/java/tech/pegasys/pantheon/consensus/ibft/statemachine/BlockHeightManager.java

@@ -0,0 +1,46 @@
+/*
+ * Copyright 2019 ConsenSys AG.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with
+ * the License. You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on
+ * an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the
+ * specific language governing permissions and limitations under the License.
+ */
+package tech.pegasys.pantheon.consensus.ibft.statemachine;
+
+import tech.pegasys.pantheon.consensus.ibft.ConsensusRoundIdentifier;
+import tech.pegasys.pantheon.consensus.ibft.ibftevent.RoundExpiry;
+import tech.pegasys.pantheon.consensus.ibft.payload.CommitPayload;
+import tech.pegasys.pantheon.consensus.ibft.payload.NewRoundPayload;
+import tech.pegasys.pantheon.consensus.ibft.payload.PreparePayload;
+import tech.pegasys.pantheon.consensus.ibft.payload.ProposalPayload;
+import tech.pegasys.pantheon.consensus.ibft.payload.RoundChangePayload;
+import tech.pegasys.pantheon.consensus.ibft.payload.SignedData;
+import tech.pegasys.pantheon.ethereum.core.BlockHeader;
+
+public interface BlockHeightManager {
+
+  void start();
+
+  void handleBlockTimerExpiry(ConsensusRoundIdentifier roundIdentifier);
+
+  void roundExpired(RoundExpiry expire);
+
+  void handleProposalPayload(SignedData<ProposalPayload> signedPayload);
+
+  void handlePreparePayload(SignedData<PreparePayload> signedPayload);
+
+  void handleCommitPayload(SignedData<CommitPayload> payload);
+
+  void handleRoundChangePayload(SignedData<RoundChangePayload> signedPayload);
+
+  void handleNewRoundPayload(SignedData<NewRoundPayload> signedPayload);
+
+  long getChainHeight();
+
+  BlockHeader getParentBlockHeader();
+}

consensus/ibft/src/main/java/tech/pegasys/pantheon/consensus/ibft/statemachine/IbftBlockHeightManager.java

@@ -53,13 +53,7 @@ import org.apache.logging.log4j.Logger;
  * and sends a Proposal message. If the round times out prior to importing a block, this class is
  * responsible for creating a RoundChange message and transmitting it.
  */
-public class IbftBlockHeightManager {
+public class IbftBlockHeightManager implements BlockHeightManager {
-
-  protected enum MessageAge {
-    PRIOR_ROUND,
-    CURRENT_ROUND,
-    FUTURE_ROUND
-  }
 
   private static final Logger LOG = LogManager.getLogger();
 
@@ -107,6 +101,7 @@ public class IbftBlockHeightManager {
                 messageValidatorFactory.createMessageValidator(roundIdentifier, parentHeader));
   }
 
+  @Override
   public void start() {
     startNewRound(0);
     if (finalState.isLocalNodeProposerForRound(currentRound.getRoundIdentifier())) {
@@ -114,6 +109,7 @@ public class IbftBlockHeightManager {
     }
   }
 
+  @Override
   public void handleBlockTimerExpiry(final ConsensusRoundIdentifier roundIdentifier) {
     if (roundIdentifier.equals(currentRound.getRoundIdentifier())) {
       currentRound.createAndSendProposalMessage(clock.millis() / 1000);
@@ -125,6 +121,7 @@ public class IbftBlockHeightManager {
     }
   }
 
+  @Override
   public void roundExpired(final RoundExpiry expire) {
     if (!expire.getView().equals(currentRound.getRoundIdentifier())) {
       LOG.info("Ignoring Round timer expired which does not match current round.");
@@ -151,18 +148,21 @@ public class IbftBlockHeightManager {
     handleRoundChangePayload(localRoundChange);
   }
 
+  @Override
   public void handleProposalPayload(final SignedData<ProposalPayload> signedPayload) {
     LOG.info("Received a Proposal Payload.");
     actionOrBufferMessage(
         signedPayload, currentRound::handleProposalMessage, RoundState::setProposedBlock);
   }
 
+  @Override
   public void handlePreparePayload(final SignedData<PreparePayload> signedPayload) {
     LOG.info("Received a prepare Payload.");
     actionOrBufferMessage(
         signedPayload, currentRound::handlePrepareMessage, RoundState::addPrepareMessage);
   }
 
+  @Override
   public void handleCommitPayload(final SignedData<CommitPayload> payload) {
     LOG.info("Received a commit Payload.");
     actionOrBufferMessage(payload, currentRound::handleCommitMessage, RoundState::addCommitMessage);
@@ -185,6 +185,7 @@ public class IbftBlockHeightManager {
     }
   }
 
+  @Override
   public void handleRoundChangePayload(final SignedData<RoundChangePayload> signedPayload) {
     final ConsensusRoundIdentifier targetRound = signedPayload.getPayload().getRoundIdentifier();
     LOG.info("Received a RoundChange Payload for {}", targetRound.toString());
@@ -223,6 +224,7 @@ public class IbftBlockHeightManager {
     roundTimer.startTimer(currentRound.getRoundIdentifier());
   }
 
+  @Override
   public void handleNewRoundPayload(final SignedData<NewRoundPayload> signedPayload) {
     final NewRoundPayload payload = signedPayload.getPayload();
     final MessageAge messageAge = determineAgeOfPayload(payload);
@@ -241,10 +243,12 @@ public class IbftBlockHeightManager {
     }
   }
 
+  @Override
   public long getChainHeight() {
     return currentRound.getRoundIdentifier().getSequenceNumber();
   }
 
+  @Override
   public BlockHeader getParentBlockHeader() {
     return parentHeader;
   }
@@ -259,4 +263,10 @@ public class IbftBlockHeightManager {
     }
     return PRIOR_ROUND;
   }
+
+  public enum MessageAge {
+    PRIOR_ROUND,
+    CURRENT_ROUND,
+    FUTURE_ROUND
+  }
 }

consensus/ibft/src/main/java/tech/pegasys/pantheon/consensus/ibft/statemachine/IbftBlockHeightManagerFactory.java

@@ -31,7 +31,19 @@ public class IbftBlockHeightManagerFactory {
     this.messageValidatorFactory = messageValidatorFactory;
   }
 
-  public IbftBlockHeightManager create(final BlockHeader parentHeader) {
+  public BlockHeightManager create(final BlockHeader parentHeader) {
+    if (finalState.isLocalNodeValidator()) {
+      return createFullBlockHeightManager(parentHeader);
+    } else {
+      return createNoOpBlockHeightManager(parentHeader);
+    }
+  }
+
+  private BlockHeightManager createNoOpBlockHeightManager(final BlockHeader parentHeader) {
+    return new NoOpBlockHeightManager(parentHeader);
+  }
+
+  private BlockHeightManager createFullBlockHeightManager(final BlockHeader parentHeader) {
     return new IbftBlockHeightManager(
         parentHeader,
         finalState,

consensus/ibft/src/main/java/tech/pegasys/pantheon/consensus/ibft/statemachine/IbftController.java

@@ -50,7 +50,7 @@ public class IbftController {
   private final IbftFinalState ibftFinalState;
   private final IbftBlockHeightManagerFactory ibftBlockHeightManagerFactory;
   private final Map<Long, List<Message>> futureMessages;
-  private IbftBlockHeightManager currentHeightManager;
+  private BlockHeightManager currentHeightManager;
   private final IbftGossip gossiper;
 
   public IbftController(
@@ -188,7 +188,7 @@ public class IbftController {
   private boolean processMessage(final SignedData<? extends Payload> msg, final Message rawMsg) {
     final ConsensusRoundIdentifier msgRoundIdentifier = msg.getPayload().getRoundIdentifier();
     if (isMsgForCurrentHeight(msgRoundIdentifier)) {
-      return isMsgFromKnownValidator(msg);
+      return isMsgFromKnownValidator(msg) && ibftFinalState.isLocalNodeValidator();
     } else if (isMsgForFutureChainHeight(msgRoundIdentifier)) {
       addMessageToFutureMessageBuffer(msgRoundIdentifier.getSequenceNumber(), rawMsg);
     } else {

consensus/ibft/src/main/java/tech/pegasys/pantheon/consensus/ibft/statemachine/IbftFinalState.java

@@ -87,6 +87,10 @@ public class IbftFinalState {
     return getProposerForRound(roundIdentifier).equals(localAddress);
   }
 
+  public boolean isLocalNodeValidator() {
+    return getValidators().contains(localAddress);
+  }
+
   public ValidatorMulticaster getValidatorMulticaster() {
     return validatorMulticaster;
   }

consensus/ibft/src/main/java/tech/pegasys/pantheon/consensus/ibft/statemachine/NoOpBlockHeightManager.java

@@ -0,0 +1,66 @@
+/*
+ * Copyright 2019 ConsenSys AG.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with
+ * the License. You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on
+ * an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the
+ * specific language governing permissions and limitations under the License.
+ */
+package tech.pegasys.pantheon.consensus.ibft.statemachine;
+
+import tech.pegasys.pantheon.consensus.ibft.ConsensusRoundIdentifier;
+import tech.pegasys.pantheon.consensus.ibft.ibftevent.RoundExpiry;
+import tech.pegasys.pantheon.consensus.ibft.payload.CommitPayload;
+import tech.pegasys.pantheon.consensus.ibft.payload.NewRoundPayload;
+import tech.pegasys.pantheon.consensus.ibft.payload.PreparePayload;
+import tech.pegasys.pantheon.consensus.ibft.payload.ProposalPayload;
+import tech.pegasys.pantheon.consensus.ibft.payload.RoundChangePayload;
+import tech.pegasys.pantheon.consensus.ibft.payload.SignedData;
+import tech.pegasys.pantheon.ethereum.core.BlockHeader;
+
+public class NoOpBlockHeightManager implements BlockHeightManager {
+
+  private final BlockHeader parentHeader;
+
+  public NoOpBlockHeightManager(final BlockHeader parentHeader) {
+    this.parentHeader = parentHeader;
+  }
+
+  @Override
+  public void start() {}
+
+  @Override
+  public void handleBlockTimerExpiry(final ConsensusRoundIdentifier roundIdentifier) {}
+
+  @Override
+  public void roundExpired(final RoundExpiry expire) {}
+
+  @Override
+  public void handleProposalPayload(final SignedData<ProposalPayload> signedPayload) {}
+
+  @Override
+  public void handlePreparePayload(final SignedData<PreparePayload> signedPayload) {}
+
+  @Override
+  public void handleCommitPayload(final SignedData<CommitPayload> payload) {}
+
+  @Override
+  public void handleRoundChangePayload(final SignedData<RoundChangePayload> signedPayload) {}
+
+  @Override
+  public void handleNewRoundPayload(final SignedData<NewRoundPayload> signedPayload) {}
+
+  @Override
+  public long getChainHeight() {
+    return parentHeader.getNumber() + 1;
+  }
+
+  @Override
+  public BlockHeader getParentBlockHeader() {
+    return parentHeader;
+  }
+}

consensus/ibft/src/test/java/tech/pegasys/pantheon/consensus/ibft/statemachine/IbftControllerTest.java

@@ -66,7 +66,7 @@ public class IbftControllerTest {
   @Mock private IbftBlockHeightManagerFactory blockHeightManagerFactory;
   @Mock private BlockHeader chainHeadBlockHeader;
   @Mock private BlockHeader nextBlock;
-  @Mock private IbftBlockHeightManager blockHeightManager;
+  @Mock private BlockHeightManager blockHeightManager;
 
   @Mock private SignedData<ProposalPayload> signedProposal;
   private Message proposalMessage;
@@ -116,6 +116,8 @@ public class IbftControllerTest {
     when(blockHeightManager.getParentBlockHeader()).thenReturn(chainHeadBlockHeader);
 
     when(nextBlock.getNumber()).thenReturn(2L);
+
+    when(ibftFinalState.isLocalNodeValidator()).thenReturn(true);
   }
 
   @Test