Add fee cap for transactions submitted via RPC. (#1137)

- Added `--rpc-tx-feecap` command line flag.
    - Maximum transaction fees (in Wei) accepted for transaction submitted through RPC.
    - Defaulted to 1 ether.
- Updated `TransactionPool.addLocalTransaction` method: performs an additional check to verify if transaction fees don't exceed user defined fee cap (if cap is set to 0 then it is ignored and means no cap).

Signed-off-by: Abdelhamid Bakhta <abdelhamid.bakhta@consensys.net>

besu/src/main/java/org/hyperledger/besu/cli/BesuCommand.java

@@ -769,6 +769,13 @@ public class BesuCommand implements DefaultCommandValues, Runnable {
       arity = "1")
   private final Wei minTransactionGasPrice = DEFAULT_MIN_TRANSACTION_GAS_PRICE;
 
+  @Option(
+      names = {"--rpc-tx-feecap"},
+      description =
+          "Maximum transaction fees (in Wei) accepted for transaction submitted through RPC (default: ${DEFAULT-VALUE})",
+      arity = "1")
+  private final Wei txFeeCap = DEFAULT_RPC_TX_FEE_CAP;
+
   @Option(
       names = {"--min-block-occupancy-ratio"},
       description = "Minimum occupancy ratio for  a mined block (default: ${DEFAULT-VALUE})",
@@ -1938,6 +1945,7 @@ public class BesuCommand implements DefaultCommandValues, Runnable {
         .pooledTransactionHashesSize(pooledTransactionHashesSize)
         .pendingTxRetentionPeriod(pendingTxRetentionPeriod)
         .priceBump(priceBump)
+        .txFeeCap(txFeeCap)
         .build();
   }
 

besu/src/main/java/org/hyperledger/besu/cli/DefaultCommandValues.java

@@ -15,6 +15,7 @@
 package org.hyperledger.besu.cli;
 
 import org.hyperledger.besu.ethereum.core.Wei;
+import org.hyperledger.besu.ethereum.eth.transactions.TransactionPoolConfiguration;
 import org.hyperledger.besu.ethereum.p2p.config.RlpxConfiguration;
 import org.hyperledger.besu.nat.NatMethod;
 
@@ -44,6 +45,8 @@ public interface DefaultCommandValues {
   String MANDATORY_NETWORK_FORMAT_HELP = "<NETWORK>";
   String MANDATORY_NODE_ID_FORMAT_HELP = "<NODEID>";
   Wei DEFAULT_MIN_TRANSACTION_GAS_PRICE = Wei.of(1000);
+  Wei DEFAULT_RPC_TX_FEE_CAP = TransactionPoolConfiguration.DEFAULT_RPC_TX_FEE_CAP;
+
   Double DEFAULT_MIN_BLOCK_OCCUPANCY_RATIO = 0.8;
   Bytes DEFAULT_EXTRA_DATA = Bytes.EMPTY;
   long DEFAULT_MAX_REFRESH_DELAY = 3600000;

besu/src/test/java/org/hyperledger/besu/cli/BesuCommandTest.java

@@ -3170,6 +3170,24 @@ public class BesuCommandTest extends CommandTestAbstract {
             "should be a number between 0 and 100 inclusive");
   }
 
+  @Test
+  public void transactionPoolTxFeeCap() {
+    final Wei txFeeCap = Wei.fromEth(2);
+    parseCommand("--rpc-tx-feecap", txFeeCap.toString());
+    verify(mockControllerBuilder)
+        .transactionPoolConfiguration(transactionPoolConfigCaptor.capture());
+    assertThat(transactionPoolConfigCaptor.getValue().getTxFeeCap()).isEqualTo(txFeeCap);
+    assertThat(commandOutput.toString()).isEmpty();
+    assertThat(commandErrorOutput.toString()).isEmpty();
+  }
+
+  @Test
+  public void invalidTansactionPoolTxFeeCapShouldFail() {
+    parseCommand("--rpc-tx-feecap", "abcd");
+    assertThat(commandErrorOutput.toString())
+        .contains("Invalid value for option '--rpc-tx-feecap'", "cannot convert 'abcd' to Wei");
+  }
+
   @Test
   public void txMessageKeepAliveSecondsWithInvalidInputShouldFail() {
     parseCommand("--Xincoming-tx-messages-keep-alive-seconds", "acbd");

besu/src/test/resources/everything_config.toml

@@ -138,6 +138,7 @@ tx-pool-price-bump=13
 tx-pool-max-size=1234
 tx-pool-hashes-max-size=10000
 Xincoming-tx-messages-keep-alive-seconds=60
+rpc-tx-feecap=2000000000000000000
 
 # Revert Reason
 revert-reason-enabled=false

ethereum/api/src/integration-test/java/org/hyperledger/besu/ethereum/api/jsonrpc/methods/EthGetFilterChangesIntegrationTest.java

@@ -126,7 +126,8 @@ public class EthGetFilterChangesIntegrationTest {
             Optional.of(peerPendingTransactionTracker),
             Wei.ZERO,
             metricsSystem,
-            Optional.empty());
+            Optional.empty(),
+            TransactionPoolConfiguration.DEFAULT);
     final BlockchainQueries blockchainQueries =
         new BlockchainQueries(blockchain, protocolContext.getWorldStateArchive());
     filterManager =

ethereum/api/src/main/java/org/hyperledger/besu/ethereum/api/graphql/internal/response/GraphQLError.java

@@ -38,6 +38,7 @@ public enum GraphQLError {
   WRONG_CHAIN_ID(-32000, "Wrong Chain ID in transaction signature"),
   REPLAY_PROTECTED_SIGNATURES_NOT_SUPPORTED(
       -32000, "Signatures with replay protection are not supported"),
+  TX_FEECAP_EXCEEDED(-32000, "Transaction fee cap exceeded"),
 
   // Private Transaction Errors
   PRIVATE_TRANSACTION_FAILED(-32000, "Private transaction failed"),
@@ -91,6 +92,8 @@ public enum GraphQLError {
         return PRIVATE_TRANSACTION_FAILED;
       case GAS_PRICE_TOO_LOW:
         return GAS_PRICE_TOO_LOW;
+      case TX_FEECAP_EXCEEDED:
+        return TX_FEECAP_EXCEEDED;
       default:
         return INTERNAL_ERROR;
     }

ethereum/api/src/main/java/org/hyperledger/besu/ethereum/api/jsonrpc/JsonRpcErrorConverter.java

@@ -47,6 +47,8 @@ public class JsonRpcErrorConverter {
         return JsonRpcError.CHAIN_HEAD_WORLD_STATE_NOT_AVAILABLE;
       case GAS_PRICE_TOO_LOW:
         return JsonRpcError.GAS_PRICE_TOO_LOW;
+      case TX_FEECAP_EXCEEDED:
+        return JsonRpcError.TX_FEECAP_EXCEEDED;
       case OFFCHAIN_PRIVACY_GROUP_DOES_NOT_EXIST:
         return JsonRpcError.OFFCHAIN_PRIVACY_GROUP_DOES_NOT_EXIST;
       case TRANSACTION_ALREADY_KNOWN:

ethereum/api/src/main/java/org/hyperledger/besu/ethereum/api/jsonrpc/internal/response/JsonRpcError.java

@@ -59,6 +59,7 @@ public enum JsonRpcError {
   GAS_PRICE_TOO_LOW(-32009, "Gas price below configured minimum gas price"),
   WRONG_CHAIN_ID(-32000, "Wrong chainId"),
   REPLAY_PROTECTED_SIGNATURES_NOT_SUPPORTED(-32000, "ChainId not supported"),
+  TX_FEECAP_EXCEEDED(-32000, "Transaction fee cap exceeded"),
 
   // Miner failures
   COINBASE_NOT_SET(-32010, "Coinbase not set. Unable to start mining without a coinbase"),

ethereum/api/src/test/java/org/hyperledger/besu/ethereum/api/jsonrpc/internal/methods/EthSendRawTransactionTest.java

@@ -170,6 +170,12 @@ public class EthSendRawTransactionTest {
         TransactionInvalidReason.TX_SENDER_NOT_AUTHORIZED, JsonRpcError.TX_SENDER_NOT_AUTHORIZED);
   }
 
+  @Test
+  public void transactionWithFeeCapExceededIsRejected() {
+    verifyErrorForInvalidTransaction(
+        TransactionInvalidReason.TX_FEECAP_EXCEEDED, JsonRpcError.TX_FEECAP_EXCEEDED);
+  }
+
   private void verifyErrorForInvalidTransaction(
       final TransactionInvalidReason transactionInvalidReason, final JsonRpcError expectedError) {
     when(transactionPool.addLocalTransaction(any(Transaction.class)))

ethereum/core/src/main/java/org/hyperledger/besu/ethereum/mainnet/TransactionValidator.java

@@ -81,6 +81,7 @@ public interface TransactionValidator {
     OFFCHAIN_PRIVACY_GROUP_DOES_NOT_EXIST,
     INCORRECT_PRIVATE_NONCE,
     GAS_PRICE_TOO_LOW,
+    TX_FEECAP_EXCEEDED,
     PRIVATE_VALUE_NOT_ZERO,
     PRIVATE_UNIMPLEMENTED_TRANSACTION_TYPE;
   }

ethereum/core/src/main/java/org/hyperledger/besu/ethereum/mainnet/ValidationResult.java

@@ -33,7 +33,7 @@ public final class ValidationResult<T> {
   }
 
   public boolean isValid() {
-    return !invalidReason.isPresent();
+    return invalidReason.isEmpty();
   }
 
   public T getInvalidReason() throws NoSuchElementException {

ethereum/eth/src/main/java/org/hyperledger/besu/ethereum/eth/transactions/TransactionPool.java

@@ -83,6 +83,7 @@ public class TransactionPool implements BlockAddedObserver {
       TransactionPriceCalculator.frontier();
   private final TransactionPriceCalculator eip1559PriceCalculator =
       TransactionPriceCalculator.eip1559();
+  private final TransactionPoolConfiguration configuration;
 
   public TransactionPool(
       final PendingTransactions pendingTransactions,
@@ -96,7 +97,8 @@ public class TransactionPool implements BlockAddedObserver {
       final Optional<PeerPendingTransactionTracker> peerPendingTransactionTracker,
       final Wei minTransactionGasPrice,
       final MetricsSystem metricsSystem,
-      final Optional<EIP1559> eip1559) {
+      final Optional<EIP1559> eip1559,
+      final TransactionPoolConfiguration configuration) {
     this.pendingTransactions = pendingTransactions;
     this.protocolSchedule = protocolSchedule;
     this.protocolContext = protocolContext;
@@ -107,6 +109,7 @@ public class TransactionPool implements BlockAddedObserver {
     this.peerPendingTransactionTracker = peerPendingTransactionTracker;
     this.minTransactionGasPrice = minTransactionGasPrice;
     this.eip1559 = eip1559;
+    this.configuration = configuration;
 
     duplicateTransactionCounter =
         metricsSystem.createLabelledCounter(
@@ -152,6 +155,12 @@ public class TransactionPool implements BlockAddedObserver {
     if (transactionGasPrice.compareTo(minTransactionGasPrice) < 0) {
       return ValidationResult.invalid(TransactionInvalidReason.GAS_PRICE_TOO_LOW);
     }
+
+    if (!configuration.getTxFeeCap().isZero()
+        && transactionGasPrice.compareTo(configuration.getTxFeeCap()) > 0) {
+      return ValidationResult.invalid(TransactionInvalidReason.TX_FEECAP_EXCEEDED);
+    }
+
     final ValidationResult<TransactionInvalidReason> validationResult =
         validateTransaction(transaction);
     if (validationResult.isValid()) {

ethereum/eth/src/main/java/org/hyperledger/besu/ethereum/eth/transactions/TransactionPoolConfiguration.java

@@ -14,6 +14,7 @@
  */
 package org.hyperledger.besu.ethereum.eth.transactions;
 
+import org.hyperledger.besu.ethereum.core.Wei;
 import org.hyperledger.besu.util.number.Percentage;
 
 import java.util.Objects;
@@ -24,25 +25,31 @@ public class TransactionPoolConfiguration {
   public static final int MAX_PENDING_TRANSACTIONS_HASHES = 4096;
   public static final int DEFAULT_TX_RETENTION_HOURS = 13;
   public static final Percentage DEFAULT_PRICE_BUMP = Percentage.fromInt(10);
+  public static final Wei DEFAULT_RPC_TX_FEE_CAP = Wei.fromEth(1);
+  public static final TransactionPoolConfiguration DEFAULT =
+      TransactionPoolConfiguration.builder().build();
 
   private final int txPoolMaxSize;
   private final int pooledTransactionHashesSize;
   private final int pendingTxRetentionPeriod;
   private final int txMessageKeepAliveSeconds;
-
   private final Percentage priceBump;
 
+  private final Wei txFeeCap;
+
   public TransactionPoolConfiguration(
       final int txPoolMaxSize,
       final int pooledTransactionHashesSize,
       final int pendingTxRetentionPeriod,
       final int txMessageKeepAliveSeconds,
-      final Percentage priceBump) {
+      final Percentage priceBump,
+      final Wei txFeeCap) {
     this.txPoolMaxSize = txPoolMaxSize;
     this.pooledTransactionHashesSize = pooledTransactionHashesSize;
     this.pendingTxRetentionPeriod = pendingTxRetentionPeriod;
     this.txMessageKeepAliveSeconds = txMessageKeepAliveSeconds;
     this.priceBump = priceBump;
+    this.txFeeCap = txFeeCap;
   }
 
   public int getTxPoolMaxSize() {
@@ -65,6 +72,10 @@ public class TransactionPoolConfiguration {
     return priceBump;
   }
 
+  public Wei getTxFeeCap() {
+    return txFeeCap;
+  }
+
   @Override
   public boolean equals(final Object o) {
     if (this == o) {
@@ -77,13 +88,14 @@ public class TransactionPoolConfiguration {
     return txPoolMaxSize == that.txPoolMaxSize
         && Objects.equals(pendingTxRetentionPeriod, that.pendingTxRetentionPeriod)
         && Objects.equals(txMessageKeepAliveSeconds, that.txMessageKeepAliveSeconds)
-        && Objects.equals(priceBump, that.priceBump);
+        && Objects.equals(priceBump, that.priceBump)
+        && Objects.equals(txFeeCap, that.txFeeCap);
   }
 
   @Override
   public int hashCode() {
     return Objects.hash(
-        txPoolMaxSize, pendingTxRetentionPeriod, txMessageKeepAliveSeconds, priceBump);
+        txPoolMaxSize, pendingTxRetentionPeriod, txMessageKeepAliveSeconds, priceBump, txFeeCap);
   }
 
   @Override
@@ -97,6 +109,8 @@ public class TransactionPoolConfiguration {
         + txMessageKeepAliveSeconds
         + ", priceBump="
         + priceBump
+        + ", txFeeCap="
+        + txFeeCap
         + '}';
   }
 
@@ -110,6 +124,7 @@ public class TransactionPoolConfiguration {
     private Integer txMessageKeepAliveSeconds = DEFAULT_TX_MSG_KEEP_ALIVE;
     private int pooledTransactionHashesSize = MAX_PENDING_TRANSACTIONS_HASHES;
     private Percentage priceBump = DEFAULT_PRICE_BUMP;
+    private Wei txFeeCap = DEFAULT_RPC_TX_FEE_CAP;
 
     public Builder txPoolMaxSize(final int txPoolMaxSize) {
       this.txPoolMaxSize = txPoolMaxSize;
@@ -140,13 +155,19 @@ public class TransactionPoolConfiguration {
       return priceBump(Percentage.fromInt(priceBump));
     }
 
+    public Builder txFeeCap(final Wei txFeeCap) {
+      this.txFeeCap = txFeeCap;
+      return this;
+    }
+
     public TransactionPoolConfiguration build() {
       return new TransactionPoolConfiguration(
           txPoolMaxSize,
           pooledTransactionHashesSize,
           pendingTxRetentionPeriod,
           txMessageKeepAliveSeconds,
-          priceBump);
+          priceBump,
+          txFeeCap);
     }
   }
 }

ethereum/eth/src/main/java/org/hyperledger/besu/ethereum/eth/transactions/TransactionPoolFactory.java

@@ -125,7 +125,8 @@ public class TransactionPoolFactory {
             pendingTransactionTracker,
             minTransactionGasPrice,
             metricsSystem,
-            eip1559);
+            eip1559,
+            transactionPoolConfiguration);
     final TransactionsMessageHandler transactionsMessageHandler =
         new TransactionsMessageHandler(
             ethContext.getScheduler(),

ethereum/eth/src/test/java/org/hyperledger/besu/ethereum/eth/transactions/TransactionPoolFactoryTest.java

@@ -90,7 +90,12 @@ public class TransactionPoolFactoryTest {
             state,
             Wei.of(1),
             new TransactionPoolConfiguration(
-                1, 1, 1, 1, TransactionPoolConfiguration.DEFAULT_PRICE_BUMP),
+                1,
+                1,
+                1,
+                1,
+                TransactionPoolConfiguration.DEFAULT_PRICE_BUMP,
+                TransactionPoolConfiguration.DEFAULT_RPC_TX_FEE_CAP),
             pendingTransactions,
             peerTransactionTracker,
             transactionsMessageSender,
@@ -168,7 +173,12 @@ public class TransactionPoolFactoryTest {
             state,
             Wei.of(1),
             new TransactionPoolConfiguration(
-                1, 1, 1, 1, TransactionPoolConfiguration.DEFAULT_PRICE_BUMP),
+                1,
+                1,
+                1,
+                1,
+                TransactionPoolConfiguration.DEFAULT_PRICE_BUMP,
+                TransactionPoolConfiguration.DEFAULT_RPC_TX_FEE_CAP),
             pendingTransactions,
             peerTransactionTracker,
             transactionsMessageSender,

ethereum/eth/src/test/java/org/hyperledger/besu/ethereum/eth/transactions/TransactionPoolTest.java

@@ -148,7 +148,8 @@ public class TransactionPoolTest {
             Optional.of(peerPendingTransactionTracker),
             Wei.of(2),
             metricsSystem,
-            Optional.empty());
+            Optional.empty(),
+            TransactionPoolConfiguration.DEFAULT);
     blockchain.observeBlockAdded(transactionPool);
   }
 
@@ -404,7 +405,8 @@ public class TransactionPoolTest {
             Optional.of(peerPendingTransactionTracker),
             Wei.ZERO,
             metricsSystem,
-            Optional.empty());
+            Optional.empty(),
+            TransactionPoolConfiguration.DEFAULT);
 
     when(pendingTransactions.containsTransaction(transaction1.getHash())).thenReturn(true);
 
@@ -541,7 +543,8 @@ public class TransactionPoolTest {
             Optional.of(peerPendingTransactionTracker),
             Wei.ZERO,
             metricsSystem,
-            Optional.empty());
+            Optional.empty(),
+            TransactionPoolConfiguration.DEFAULT);
 
     final TransactionTestFixture builder = new TransactionTestFixture();
     final Transaction transaction1 = builder.nonce(1).createTransaction(KEY_PAIR1);
@@ -610,7 +613,8 @@ public class TransactionPoolTest {
             Optional.of(peerPendingTransactionTracker),
             Wei.ZERO,
             metricsSystem,
-            Optional.empty());
+            Optional.empty(),
+            TransactionPoolConfiguration.DEFAULT);
 
     final TransactionTestFixture builder = new TransactionTestFixture();
     final Transaction transactionLocal = builder.nonce(1).createTransaction(KEY_PAIR1);
@@ -650,6 +654,75 @@ public class TransactionPoolTest {
         .isEqualToComparingFieldByField(expectedValidationParams);
   }
 
+  @Test
+  public void shouldIgnoreFeeCapIfSetZero() {
+    final EthProtocolManager ethProtocolManager = EthProtocolManagerTestUtil.create();
+    final EthContext ethContext = ethProtocolManager.ethContext();
+    final PeerTransactionTracker peerTransactionTracker = new PeerTransactionTracker();
+    final Wei twoEthers = Wei.fromEth(2);
+    final TransactionPool transactionPool =
+        new TransactionPool(
+            transactions,
+            protocolSchedule,
+            protocolContext,
+            batchAddedListener,
+            Optional.of(pendingBatchAddedListener),
+            syncState,
+            ethContext,
+            peerTransactionTracker,
+            Optional.of(peerPendingTransactionTracker),
+            Wei.ZERO,
+            metricsSystem,
+            Optional.empty(),
+            TransactionPoolConfiguration.builder().txFeeCap(Wei.ZERO).build());
+    when(transactionValidator.validate(any(Transaction.class))).thenReturn(valid());
+    when(transactionValidator.validateForSender(
+            any(Transaction.class),
+            nullable(Account.class),
+            any(TransactionValidationParams.class)))
+        .thenReturn(valid());
+    assertThat(
+            transactionPool
+                .addLocalTransaction(
+                    new TransactionTestFixture()
+                        .nonce(1)
+                        .gasPrice(twoEthers.add(Wei.of(1)))
+                        .createTransaction(KEY_PAIR1))
+                .isValid())
+        .isTrue();
+  }
+
+  @Test
+  public void shouldRejectLocalTransactionIfFeeCapExceeded() {
+    final EthProtocolManager ethProtocolManager = EthProtocolManagerTestUtil.create();
+    final EthContext ethContext = ethProtocolManager.ethContext();
+    final PeerTransactionTracker peerTransactionTracker = new PeerTransactionTracker();
+    final Wei twoEthers = Wei.fromEth(2);
+    TransactionPool transactionPool =
+        new TransactionPool(
+            transactions,
+            protocolSchedule,
+            protocolContext,
+            batchAddedListener,
+            Optional.of(pendingBatchAddedListener),
+            syncState,
+            ethContext,
+            peerTransactionTracker,
+            Optional.of(peerPendingTransactionTracker),
+            Wei.ZERO,
+            metricsSystem,
+            Optional.empty(),
+            TransactionPoolConfiguration.builder().txFeeCap(twoEthers).build());
+
+    final TransactionTestFixture builder = new TransactionTestFixture();
+    final Transaction transactionLocal =
+        builder.nonce(1).gasPrice(twoEthers.add(Wei.of(1))).createTransaction(KEY_PAIR1);
+
+    final ValidationResult<TransactionInvalidReason> result =
+        transactionPool.addLocalTransaction(transactionLocal);
+    assertThat(result.getInvalidReason()).isEqualTo(TransactionInvalidReason.TX_FEECAP_EXCEEDED);
+  }
+
   private void assertTransactionPending(final Transaction t) {
     assertThat(transactions.getTransactionByHash(t.getHash())).contains(t);
   }