New filter restricting delegations in txpool

src/Nethermind/Nethermind.TxPool.Test/OnlyOneTxPerDelegatedAccountFilterTest.cs

@@ -0,0 +1,161 @@
+// SPDX-FileCopyrightText: 2024 Demerzel Solutions Limited
+// SPDX-License-Identifier: LGPL-3.0-only
+
+using Nethermind.Core;
+using Nethermind.Core.Specs;
+using Nethermind.Core.Test.Builders;
+using Nethermind.Crypto;
+using Nethermind.Db;
+using Nethermind.Evm;
+using Nethermind.Logging;
+using Nethermind.Specs.Forks;
+using Nethermind.State;
+using Nethermind.Trie.Pruning;
+using Nethermind.TxPool.Collections;
+using Nethermind.TxPool.Filters;
+using NSubstitute;
+using NUnit.Framework;
+using Org.BouncyCastle.Pqc.Crypto.Lms;
+using System;
+using System.Collections;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+
+namespace Nethermind.TxPool.Test;
+internal class OnlyOneTxPerDelegatedAccountFilterTest
+{
+    [Test]
+    public void Accept_SenderIsNotDelegated_ReturnsAccepted()
+    {
+        IChainHeadSpecProvider headInfoProvider = Substitute.For<IChainHeadSpecProvider>();
+        headInfoProvider.GetCurrentHeadSpec().Returns(Prague.Instance);
+        TxDistinctSortedPool standardPool = new TxDistinctSortedPool(MemoryAllowance.MemPoolSize, Substitute.For<IComparer<Transaction>>(), NullLogManager.Instance);
+        TxDistinctSortedPool blobPool = new BlobTxDistinctSortedPool(10, Substitute.For<IComparer<Transaction>>(), NullLogManager.Instance);
+        OnlyOneTxPerDelegatedAccountFilter filter = new(headInfoProvider, standardPool, blobPool, Substitute.For<IReadOnlyStateProvider>(), new CodeInfoRepository(), new DelegationCache());
+        Transaction transaction = Build.A.Transaction.SignedAndResolved(new EthereumEcdsa(0), TestItem.PrivateKeyA).TestObject;
+        TxFilteringState state = new();
+
+        AcceptTxResult result = filter.Accept(transaction, ref state, TxHandlingOptions.None);
+
+        Assert.That(result, Is.EqualTo(AcceptTxResult.Accepted));
+    }
+
+    [Test]
+    public void Accept_SenderIsDelegatedWithNoTransactionsInPool_ReturnsAccepted()
+    {
+        IChainHeadSpecProvider headInfoProvider = Substitute.For<IChainHeadSpecProvider>();
+        headInfoProvider.GetCurrentHeadSpec().Returns(Prague.Instance);
+        TxDistinctSortedPool standardPool = new TxDistinctSortedPool(MemoryAllowance.MemPoolSize, Substitute.For<IComparer<Transaction>>(), NullLogManager.Instance);
+        TxDistinctSortedPool blobPool = new BlobTxDistinctSortedPool(10, Substitute.For<IComparer<Transaction>>(), NullLogManager.Instance);
+        OnlyOneTxPerDelegatedAccountFilter filter = new(headInfoProvider, standardPool, blobPool, Substitute.For<IReadOnlyStateProvider>(), new CodeInfoRepository(), new DelegationCache());
+        Transaction transaction = Build.A.Transaction.SignedAndResolved(new EthereumEcdsa(0), TestItem.PrivateKeyA).TestObject;
+        TxFilteringState state = new();
+
+        AcceptTxResult result = filter.Accept(transaction, ref state, TxHandlingOptions.None);
+
+        Assert.That(result, Is.EqualTo(AcceptTxResult.Accepted));
+    }
+
+    [Test]
+    public void Accept_SenderIsDelegatedWithOneTransactionInPoolWithSameNonce_ReturnsAccepted()
+    {
+        IChainHeadSpecProvider headInfoProvider = Substitute.For<IChainHeadSpecProvider>();
+        headInfoProvider.GetCurrentHeadSpec().Returns(Prague.Instance);
+        TxDistinctSortedPool standardPool = new TxDistinctSortedPool(MemoryAllowance.MemPoolSize, Substitute.For<IComparer<Transaction>>(), NullLogManager.Instance);
+        TxDistinctSortedPool blobPool = new BlobTxDistinctSortedPool(10, Substitute.For<IComparer<Transaction>>(), NullLogManager.Instance);
+        Transaction inPool = Build.A.Transaction.SignedAndResolved(new EthereumEcdsa(0), TestItem.PrivateKeyA).TestObject;
+        standardPool.TryInsert(inPool.Hash, inPool);
+        IDb stateDb = new MemDb();
+        IDb codeDb = new MemDb();
+        TrieStore trieStore = new(stateDb, LimboLogs.Instance);
+        IWorldState stateProvider = new WorldState(trieStore, codeDb, LimboLogs.Instance);
+        stateProvider.CreateAccount(TestItem.AddressA, 0);
+        CodeInfoRepository codeInfoRepository = new();
+        byte[] code = [.. Eip7702Constants.DelegationHeader, .. TestItem.PrivateKeyA.Address.Bytes];
+        codeInfoRepository.InsertCode(stateProvider, code, TestItem.AddressA, Prague.Instance);
+        OnlyOneTxPerDelegatedAccountFilter filter = new(headInfoProvider, standardPool, blobPool, stateProvider, codeInfoRepository, new DelegationCache());
+        Transaction transaction = Build.A.Transaction.SignedAndResolved(new EthereumEcdsa(0), TestItem.PrivateKeyA).TestObject;
+        TxFilteringState state = new();
+
+        AcceptTxResult result = filter.Accept(transaction, ref state, TxHandlingOptions.None);
+
+        Assert.That(result, Is.EqualTo(AcceptTxResult.Accepted));
+    }
+
+    [Test]
+    public void Accept_SenderIsDelegatedWithOneTransactionInPoolWithDifferentNonce_ReturnsOnlyOneTxPerDelegatedAccount()
+    {
+        IChainHeadSpecProvider headInfoProvider = Substitute.For<IChainHeadSpecProvider>();
+        headInfoProvider.GetCurrentHeadSpec().Returns(Prague.Instance);
+        TxDistinctSortedPool standardPool = new TxDistinctSortedPool(MemoryAllowance.MemPoolSize, Substitute.For<IComparer<Transaction>>(), NullLogManager.Instance);
+        TxDistinctSortedPool blobPool = new BlobTxDistinctSortedPool(10, Substitute.For<IComparer<Transaction>>(), NullLogManager.Instance);
+        Transaction inPool = Build.A.Transaction.SignedAndResolved(new EthereumEcdsa(0), TestItem.PrivateKeyA).TestObject;
+        standardPool.TryInsert(inPool.Hash, inPool);
+        IDb stateDb = new MemDb();
+        IDb codeDb = new MemDb();
+        TrieStore trieStore = new(stateDb, LimboLogs.Instance);
+        IWorldState stateProvider = new WorldState(trieStore, codeDb, LimboLogs.Instance);
+        stateProvider.CreateAccount(TestItem.AddressA, 0);
+        CodeInfoRepository codeInfoRepository = new();
+        byte[] code = [.. Eip7702Constants.DelegationHeader, .. TestItem.PrivateKeyA.Address.Bytes];
+        codeInfoRepository.InsertCode(stateProvider, code, TestItem.AddressA, Prague.Instance);
+        OnlyOneTxPerDelegatedAccountFilter filter = new(headInfoProvider, standardPool, blobPool, stateProvider, codeInfoRepository, new DelegationCache());
+        Transaction transaction = Build.A.Transaction.WithNonce(1).SignedAndResolved(new EthereumEcdsa(0), TestItem.PrivateKeyA).TestObject;
+        TxFilteringState state = new();
+
+        AcceptTxResult result = filter.Accept(transaction, ref state, TxHandlingOptions.None);
+
+        Assert.That(result, Is.EqualTo(AcceptTxResult.OnlyOneTxPerDelegatedAccount));
+    }
+
+    private static object[] EipActiveCases =
+    {
+        new object[]{ true, AcceptTxResult.OnlyOneTxPerDelegatedAccount },
+        new object[]{ false, AcceptTxResult.Accepted},
+    };
+    [TestCaseSource(nameof(EipActiveCases))]
+    public void Accept_Eip7702IsNotActivated_ReturnsExpected(bool isActive, AcceptTxResult expected)
+    {
+        IChainHeadSpecProvider headInfoProvider = Substitute.For<IChainHeadSpecProvider>();
+        headInfoProvider.GetCurrentHeadSpec().Returns(isActive ? Prague.Instance : Cancun.Instance);
+        TxDistinctSortedPool standardPool = new TxDistinctSortedPool(MemoryAllowance.MemPoolSize, Substitute.For<IComparer<Transaction>>(), NullLogManager.Instance);
+        TxDistinctSortedPool blobPool = new BlobTxDistinctSortedPool(10, Substitute.For<IComparer<Transaction>>(), NullLogManager.Instance);
+        Transaction inPool = Build.A.Transaction.SignedAndResolved(new EthereumEcdsa(0), TestItem.PrivateKeyA).TestObject;
+        standardPool.TryInsert(inPool.Hash, inPool);
+        IDb stateDb = new MemDb();
+        IDb codeDb = new MemDb();
+        TrieStore trieStore = new(stateDb, LimboLogs.Instance);
+        IWorldState stateProvider = new WorldState(trieStore, codeDb, LimboLogs.Instance);
+        stateProvider.CreateAccount(TestItem.AddressA, 0);
+        CodeInfoRepository codeInfoRepository = new();
+        byte[] code = [.. Eip7702Constants.DelegationHeader, .. TestItem.PrivateKeyA.Address.Bytes];
+        codeInfoRepository.InsertCode(stateProvider, code, TestItem.AddressA, Prague.Instance);
+        OnlyOneTxPerDelegatedAccountFilter filter = new(headInfoProvider, standardPool, blobPool, stateProvider, codeInfoRepository, new DelegationCache());
+        Transaction transaction = Build.A.Transaction.WithNonce(1).SignedAndResolved(new EthereumEcdsa(0), TestItem.PrivateKeyA).TestObject;
+        TxFilteringState state = new();
+
+        AcceptTxResult result = filter.Accept(transaction, ref state, TxHandlingOptions.None);
+
+        Assert.That(result, Is.EqualTo(expected));
+    }
+
+    [Test]
+    public void Accept_SenderHasPendingDelegation_ReturnsPendingDelegation()
+    {
+        IChainHeadSpecProvider headInfoProvider = Substitute.For<IChainHeadSpecProvider>();
+        headInfoProvider.GetCurrentHeadSpec().Returns(Prague.Instance);
+        TxDistinctSortedPool standardPool = new TxDistinctSortedPool(MemoryAllowance.MemPoolSize, Substitute.For<IComparer<Transaction>>(), NullLogManager.Instance);
+        TxDistinctSortedPool blobPool = new BlobTxDistinctSortedPool(10, Substitute.For<IComparer<Transaction>>(), NullLogManager.Instance);
+        DelegationCache pendingDelegations = new();
+        pendingDelegations.IncrementDelegationCount(TestItem.AddressA, 0);
+        OnlyOneTxPerDelegatedAccountFilter filter = new(headInfoProvider, standardPool, blobPool, Substitute.For<IReadOnlyStateProvider>(), new CodeInfoRepository(), pendingDelegations);
+        Transaction transaction = Build.A.Transaction.WithNonce(0).SignedAndResolved(new EthereumEcdsa(0), TestItem.PrivateKeyA).TestObject;
+        TxFilteringState state = new();
+
+        AcceptTxResult result = filter.Accept(transaction, ref state, TxHandlingOptions.None);
+
+        Assert.That(result, Is.EqualTo(AcceptTxResult.PendingDelegation));
+    }
+}

src/Nethermind/Nethermind.TxPool.Test/TxPoolTests.cs

@@ -1770,6 +1770,89 @@ public void SubmitTx_CodeIsNotDelegationAndDelegation_DelegationIsAccepted((byte
             result.Should().Be(testCase.expected);
         }
 
+        [Test]
+        public void Delegated_account_can_only_have_one_tx()
+        {
+            ISpecProvider specProvider = GetPragueSpecProvider();
+            TxPoolConfig txPoolConfig = new TxPoolConfig { Size = 30, PersistentBlobStorageSize = 0 };
+            _txPool = CreatePool(txPoolConfig, specProvider);
+
+            PrivateKey signer = TestItem.PrivateKeyA;
+            _stateProvider.CreateAccount(signer.Address, UInt256.MaxValue);
+            byte[] delegation = [.. Eip7702Constants.DelegationHeader, .. TestItem.AddressC.Bytes];
+            _stateProvider.InsertCode(signer.Address, delegation.AsMemory(), Prague.Instance);
+
+            Transaction firstTx = Build.A.Transaction
+                .WithNonce(0)
+                .WithType(TxType.EIP1559)
+                .WithMaxFeePerGas(9.GWei())
+                .WithMaxPriorityFeePerGas(9.GWei())
+                .WithGasLimit(GasCostOf.Transaction)
+                .WithTo(TestItem.AddressB)
+                .SignedAndResolved(_ethereumEcdsa, signer).TestObject;
+
+            AcceptTxResult result = _txPool.SubmitTx(firstTx, TxHandlingOptions.PersistentBroadcast);
+            result.Should().Be(AcceptTxResult.Accepted);
+
+            Transaction secondTx = Build.A.Transaction
+                .WithNonce(1)
+                .WithType(TxType.EIP1559)
+                .WithMaxFeePerGas(9.GWei())
+                .WithMaxPriorityFeePerGas(9.GWei())
+                .WithGasLimit(GasCostOf.Transaction)
+                .WithTo(TestItem.AddressB)
+                .SignedAndResolved(_ethereumEcdsa, signer).TestObject;
+
+            result = _txPool.SubmitTx(secondTx, TxHandlingOptions.PersistentBroadcast);
+
+            result.Should().Be(AcceptTxResult.OnlyOneTxPerDelegatedAccount);
+        }
+
+        [Test]
+        public void Tx_with_pending_delegation_is_rejected_then_is_accepted_after_delegation_removal()
+        {
+            ISpecProvider specProvider = GetPragueSpecProvider();
+            TxPoolConfig txPoolConfig = new TxPoolConfig { Size = 30, PersistentBlobStorageSize = 0 };
+            _txPool = CreatePool(txPoolConfig, specProvider);
+
+            PrivateKey signer = TestItem.PrivateKeyA;
+            _stateProvider.CreateAccount(signer.Address, UInt256.MaxValue);
+
+            EthereumEcdsa ecdsa = new EthereumEcdsa(_specProvider.ChainId);
+
+            Transaction firstTx = Build.A.Transaction
+                .WithNonce(0)
+                .WithType(TxType.SetCode)
+                .WithMaxFeePerGas(9.GWei())
+                .WithMaxPriorityFeePerGas(9.GWei())
+                .WithGasLimit(100_000)
+                .WithAuthorizationCode(ecdsa.Sign(signer, specProvider.ChainId, TestItem.AddressC, 0))
+                .WithTo(TestItem.AddressB)
+                .SignedAndResolved(_ethereumEcdsa, signer).TestObject;
+
+            AcceptTxResult result = _txPool.SubmitTx(firstTx, TxHandlingOptions.PersistentBroadcast);
+            result.Should().Be(AcceptTxResult.Accepted);
+
+            Transaction secondTx = Build.A.Transaction
+                .WithNonce(0)
+                .WithType(TxType.EIP1559)
+                .WithMaxFeePerGas(9.GWei())
+                .WithMaxPriorityFeePerGas(9.GWei())
+                .WithGasLimit(GasCostOf.Transaction)
+                .WithTo(TestItem.AddressB)
+                .SignedAndResolved(_ethereumEcdsa, signer).TestObject;
+
+            result = _txPool.SubmitTx(secondTx, TxHandlingOptions.PersistentBroadcast);
+
+            result.Should().Be(AcceptTxResult.PendingDelegation);
+
+            _txPool.RemoveTransaction(firstTx.Hash);
+
+            result = _txPool.SubmitTx(secondTx, TxHandlingOptions.PersistentBroadcast);
+
+            result.Should().Be(AcceptTxResult.AlreadyKnown);
+        }
+
         private IDictionary<ITxPoolPeer, PrivateKey> GetPeers(int limit = 100)
         {
             var peers = new Dictionary<ITxPoolPeer, PrivateKey>();

src/Nethermind/Nethermind.TxPool/AcceptTxResult.cs

@@ -89,6 +89,15 @@ namespace Nethermind.TxPool
         /// Ignores transactions if tx type is not supported
         /// </summary>
         public static readonly AcceptTxResult NotSupportedTxType = new(15, nameof(NotSupportedTxType));
+        /// <summary>
+        /// Only one tx is allowed per delegated account. 
+        /// </summary>
+        public static readonly AcceptTxResult OnlyOneTxPerDelegatedAccount = new(16, nameof(OnlyOneTxPerDelegatedAccount));
+        /// <summary>
+        /// There is a pending delegation in the tx pool already
+        /// </summary>
+        public static readonly AcceptTxResult PendingDelegation = new(17, nameof(PendingDelegation));
+
 
         /// <summary>
         /// Transaction size exceeds configured max size.

src/Nethermind/Nethermind.TxPool/DelegationCache.cs

@@ -0,0 +1,62 @@
+// SPDX-FileCopyrightText: 2024 Demerzel Solutions Limited
+// SPDX-License-Identifier: LGPL-3.0-only
+
+using Nethermind.Core;
+using Nethermind.Int256;
+using System;
+using System.Collections.Concurrent;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+
+namespace Nethermind.TxPool;
+internal sealed class DelegationCache
+{
+    private readonly ConcurrentDictionary<UInt256, int> _pendingDelegations = new();
+
+    public bool HasPending(AddressAsKey key, UInt256 nonce)
+    {
+        return _pendingDelegations.ContainsKey(KeyMask(key, nonce));
+    }
+
+    public void DecrementDelegationCount(AddressAsKey key, UInt256 nonce)
+    {
+        InternalIncrement(key, nonce, false);
+    }
+    public void IncrementDelegationCount(AddressAsKey key, UInt256 nonce)
+    {
+        InternalIncrement(key, nonce, true);
+    }
+
+    private void InternalIncrement(AddressAsKey key, UInt256 nonce, bool increment)
+    {
+        UInt256 addressPlusNonce = KeyMask(key, nonce);
+
+        int value = increment ? 1 : -1;
+        var lastCount = _pendingDelegations.AddOrUpdate(addressPlusNonce,
+            (k) =>
+            {
+                if (increment)
+                    return 1;
+                return 0;
+            },
+            (k, c) => c + value);
+
+        if (lastCount == 0)
+        {
+            //Remove() is threadsafe and only removes if the count is the same as the updated one
+            ((ICollection<KeyValuePair<UInt256, int>>)_pendingDelegations).Remove(
+                new KeyValuePair<UInt256, int>(addressPlusNonce, lastCount));
+        }
+    }
+
+    private static UInt256 KeyMask(AddressAsKey key, UInt256 nonce)
+    {
+        //A nonce cannot exceed 2^64-1 and an address is 20 bytes, so we can pack them together in one u256
+        UInt256 addressPlusNonce = new(key.Value.Bytes);
+        nonce <<= 64 * 3;
+        addressPlusNonce += nonce;
+        return addressPlusNonce;
+    }
+}

src/Nethermind/Nethermind.TxPool/Filters/MalformedTxFilter.cs

@@ -19,7 +19,8 @@ internal sealed class MalformedTxFilter(
         public AcceptTxResult Accept(Transaction tx, ref TxFilteringState state, TxHandlingOptions txHandlingOptions)
         {
             IReleaseSpec spec = specProvider.GetCurrentHeadSpec();
-            if (!txValidator.IsWellFormed(tx, spec))
+            ValidationResult result = txValidator.IsWellFormed(tx, spec);
+            if (!result)
             {
                 Metrics.PendingTransactionsMalformed++;
                 // It may happen that other nodes send us transactions that were signed for another chain or don't have enough gas.

src/Nethermind/Nethermind.TxPool/Filters/OnlyOneTxPerDelegatedAccountFilter.cs

@@ -0,0 +1,48 @@
+using Nethermind.Core;
+using Nethermind.Core.Specs;
+using Nethermind.Evm;
+using Nethermind.Int256;
+using Nethermind.State;
+using Nethermind.TxPool.Collections;
+using System.Collections.Concurrent;
+
+namespace Nethermind.TxPool.Filters
+{
+    internal sealed class OnlyOneTxPerDelegatedAccountFilter(
+        IChainHeadSpecProvider specProvider,
+        TxDistinctSortedPool standardPool,
+        TxDistinctSortedPool blobPool,
+        IReadOnlyStateProvider worldState,
+        ICodeInfoRepository codeInfoRepository,
+        DelegationCache pendingDelegations) : IIncomingTxFilter
+    {
+        public AcceptTxResult Accept(Transaction tx, ref TxFilteringState state, TxHandlingOptions txHandlingOptions)
+        {
+            IReleaseSpec spec = specProvider.GetCurrentHeadSpec();
+            if (!spec.IsEip7702Enabled)
+                return AcceptTxResult.Accepted;
+
+            if (pendingDelegations.HasPending(tx.SenderAddress!, tx.Nonce))
+                return AcceptTxResult.PendingDelegation;
+
+            if (!codeInfoRepository.TryGetDelegation(worldState, tx.SenderAddress!, out _))
+                return AcceptTxResult.Accepted;
+            Transaction[] currentTxs;
+
+            //Transactios from the same source can only be either blob transactions or some other type 
+            if (standardPool.TryGetBucket(tx.SenderAddress!, out currentTxs) || blobPool.TryGetBucket(tx.SenderAddress!, out currentTxs))
+            {
+                foreach (Transaction existingTx in currentTxs)
+                {
+                    if (existingTx.Nonce == tx.Nonce)
+                    {
+                        //This is a replacement tx so accept it, and let the comparers check for correct replacement rules
+                        return AcceptTxResult.Accepted;
+                    }
+                }
+                return AcceptTxResult.OnlyOneTxPerDelegatedAccount;
+            }
+            return AcceptTxResult.Accepted;
+        }
+    }
+}