Header validation to ensure no empty blocks when createEmptyBlocks is…

… false

Signed-off-by: Jason Frame <jason.frame@consensys.net>

besu/src/test/java/org/hyperledger/besu/controller/TransitionControllerBuilderTest.java

@@ -199,7 +199,7 @@ public void assertPostMergeScheduleForPostMergeExactlyAtTerminalDifficultyIfNotF
   public void assertCliqueDetachedHeaderValidationPreMerge() {
     BlockHeaderValidator cliqueValidator =
         BlockHeaderValidationRulesetFactory.cliqueBlockHeaderValidator(
-                5L, new EpochManager(5L), Optional.of(FeeMarket.london(1L)), true)
+                5L, false, new EpochManager(5L), Optional.of(FeeMarket.london(1L)), true)
             .build();
     assertDetachedRulesForPostMergeBlocks(cliqueValidator);
   }

consensus/clique/src/main/java/org/hyperledger/besu/consensus/clique/BlockHeaderValidationRulesetFactory.java

@@ -20,6 +20,7 @@
 import org.hyperledger.besu.config.MergeConfigOptions;
 import org.hyperledger.besu.consensus.clique.headervalidationrules.CliqueDifficultyValidationRule;
 import org.hyperledger.besu.consensus.clique.headervalidationrules.CliqueExtraDataValidationRule;
+import org.hyperledger.besu.consensus.clique.headervalidationrules.CliqueNoEmptyBlockValidationRule;
 import org.hyperledger.besu.consensus.clique.headervalidationrules.CoinbaseHeaderValidationRule;
 import org.hyperledger.besu.consensus.clique.headervalidationrules.SignerRateLimitValidationRule;
 import org.hyperledger.besu.consensus.clique.headervalidationrules.VoteValidationRule;
@@ -57,10 +58,15 @@ public class BlockHeaderValidationRulesetFactory {
    */
   public static BlockHeaderValidator.Builder cliqueBlockHeaderValidator(
       final long secondsBetweenBlocks,
+      final boolean createEmptyBlocks,
       final EpochManager epochManager,
       final Optional<BaseFeeMarket> baseFeeMarket) {
     return cliqueBlockHeaderValidator(
-        secondsBetweenBlocks, epochManager, baseFeeMarket, MergeConfigOptions.isMergeEnabled());
+        secondsBetweenBlocks,
+        createEmptyBlocks,
+        epochManager,
+        baseFeeMarket,
+        MergeConfigOptions.isMergeEnabled());
   }
 
   /**
@@ -75,6 +81,7 @@ public static BlockHeaderValidator.Builder cliqueBlockHeaderValidator(
   @VisibleForTesting
   public static BlockHeaderValidator.Builder cliqueBlockHeaderValidator(
       final long secondsBetweenBlocks,
+      final boolean createEmptyBlocks,
       final EpochManager epochManager,
       final Optional<BaseFeeMarket> baseFeeMarket,
       final boolean isMergeEnabled) {
@@ -99,6 +106,10 @@ public static BlockHeaderValidator.Builder cliqueBlockHeaderValidator(
       builder.addRule(new BaseFeeMarketBlockHeaderGasPriceValidationRule(baseFeeMarket.get()));
     }
 
+    if (!createEmptyBlocks) {
+      builder.addRule(new CliqueNoEmptyBlockValidationRule());
+    }
+
     var mixHashRule =
         new ConstantFieldValidationRule<>("MixHash", BlockHeader::getMixHash, Hash.ZERO);
     var voteValidationRule = new VoteValidationRule();

consensus/clique/src/main/java/org/hyperledger/besu/consensus/clique/CliqueProtocolSchedule.java

@@ -78,6 +78,7 @@ public static ProtocolSchedule create(
                     applyCliqueSpecificModifications(
                         epochManager,
                         cliqueConfig.getBlockPeriodSeconds(),
+                        cliqueConfig.getCreateEmptyBlocks(),
                         localNodeAddress,
                         builder)),
             privacyParameters,
@@ -107,16 +108,19 @@ public static ProtocolSchedule create(
   private static ProtocolSpecBuilder applyCliqueSpecificModifications(
       final EpochManager epochManager,
       final long secondsBetweenBlocks,
+      final boolean createEmptyBlocks,
       final Address localNodeAddress,
       final ProtocolSpecBuilder specBuilder) {
 
     return specBuilder
         .blockHeaderValidatorBuilder(
             baseFeeMarket ->
-                getBlockHeaderValidator(epochManager, secondsBetweenBlocks, baseFeeMarket))
+                getBlockHeaderValidator(
+                    epochManager, secondsBetweenBlocks, createEmptyBlocks, baseFeeMarket))
         .ommerHeaderValidatorBuilder(
             baseFeeMarket ->
-                getBlockHeaderValidator(epochManager, secondsBetweenBlocks, baseFeeMarket))
+                getBlockHeaderValidator(
+                    epochManager, secondsBetweenBlocks, createEmptyBlocks, baseFeeMarket))
         .blockBodyValidatorBuilder(MainnetBlockBodyValidator::new)
         .blockValidatorBuilder(MainnetProtocolSpecs.blockValidatorBuilder())
         .blockImporterBuilder(MainnetBlockImporter::new)
@@ -128,11 +132,14 @@ private static ProtocolSpecBuilder applyCliqueSpecificModifications(
   }
 
   private static BlockHeaderValidator.Builder getBlockHeaderValidator(
-      final EpochManager epochManager, final long secondsBetweenBlocks, final FeeMarket feeMarket) {
+      final EpochManager epochManager,
+      final long secondsBetweenBlocks,
+      final boolean createEmptyBlocks,
+      final FeeMarket feeMarket) {
     Optional<BaseFeeMarket> baseFeeMarket =
         Optional.of(feeMarket).filter(FeeMarket::implementsBaseFee).map(BaseFeeMarket.class::cast);
 
     return BlockHeaderValidationRulesetFactory.cliqueBlockHeaderValidator(
-        secondsBetweenBlocks, epochManager, baseFeeMarket);
+        secondsBetweenBlocks, createEmptyBlocks, epochManager, baseFeeMarket);
   }
 }

consensus/clique/src/main/java/org/hyperledger/besu/consensus/clique/headervalidationrules/CliqueNoEmptyBlockValidationRule.java

@@ -0,0 +1,47 @@
+/*
+ * Copyright 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.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+package org.hyperledger.besu.consensus.clique.headervalidationrules;
+
+import org.hyperledger.besu.datatypes.Hash;
+import org.hyperledger.besu.ethereum.core.BlockHeader;
+import org.hyperledger.besu.ethereum.mainnet.DetachedBlockHeaderValidationRule;
+
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+/** The No empty block validation rule. */
+public class CliqueNoEmptyBlockValidationRule implements DetachedBlockHeaderValidationRule {
+
+  private static final Logger LOG = LoggerFactory.getLogger(CliqueNoEmptyBlockValidationRule.class);
+
+  /**
+   * Responsible for ensuring there are no empty transactions. This is used when createEmptyBlocks
+   * is false, to ensure that no empty blocks are created.
+   *
+   * @param header the block header to validate
+   * @param parent the block header corresponding to the parent of the header being validated.
+   * @return true if the transactionsRoot in the header is not the empty trie hash.
+   */
+  @Override
+  public boolean validate(final BlockHeader header, final BlockHeader parent) {
+    final boolean hasTransactions = !header.getTransactionsRoot().equals(Hash.EMPTY_TRIE_HASH);
+    if (!hasTransactions) {
+      LOG.info(
+          "Invalid block header: {} has no transactions but create empty blocks is not enabled",
+          header.getNumber());
+    }
+    return hasTransactions;
+  }
+}

consensus/clique/src/test/java/org/hyperledger/besu/consensus/clique/headervalidationrules/CliqueNoEmptyBlockValidationRuleTest.java

@@ -0,0 +1,57 @@
+/*
+ * Copyright Hyperledger Besu Contributors.
+ *
+ * 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.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+package org.hyperledger.besu.consensus.clique.headervalidationrules;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+import org.hyperledger.besu.crypto.KeyPair;
+import org.hyperledger.besu.crypto.SignatureAlgorithmFactory;
+import org.hyperledger.besu.datatypes.Hash;
+import org.hyperledger.besu.ethereum.core.BlockHeader;
+import org.hyperledger.besu.ethereum.core.BlockHeaderTestFixture;
+import org.hyperledger.besu.ethereum.core.Transaction;
+import org.hyperledger.besu.ethereum.core.TransactionTestFixture;
+import org.hyperledger.besu.ethereum.mainnet.BodyValidation;
+
+import java.util.List;
+
+import org.junit.jupiter.api.Test;
+
+class CliqueNoEmptyBlockValidationRuleTest {
+
+  @Test
+  void headerWithNoTransactionsIsInvalid() {
+    final BlockHeader blockHeader = new BlockHeaderTestFixture().buildHeader();
+
+    final CliqueNoEmptyBlockValidationRule noEmptyBlockRule =
+        new CliqueNoEmptyBlockValidationRule();
+    assertThat(noEmptyBlockRule.validate(blockHeader, null)).isFalse();
+  }
+
+  @Test
+  void headerWithTransactionsIsValid() {
+    final TransactionTestFixture transactionTestFixture = new TransactionTestFixture();
+    final KeyPair keyPair = SignatureAlgorithmFactory.getInstance().generateKeyPair();
+    final Transaction transaction = transactionTestFixture.createTransaction(keyPair);
+    final Hash transactionRoot = BodyValidation.transactionsRoot(List.of(transaction));
+    final BlockHeader blockHeader =
+        new BlockHeaderTestFixture().transactionsRoot(transactionRoot).buildHeader();
+
+    final CliqueNoEmptyBlockValidationRule noEmptyBlockRule =
+        new CliqueNoEmptyBlockValidationRule();
+    assertThat(noEmptyBlockRule.validate(blockHeader, null)).isTrue();
+  }
+}