Implement beacon chain push withdrawals (EIP-4895)

src/Nethermind/Nethermind.Consensus.Clique/CliqueBlockProducer.cs

@@ -438,7 +438,7 @@ bool IBlockProducer.IsProducingBlocks(ulong? maxProducingInterval)
         _stateProvider.StateRoot = parentHeader.StateRoot!;
 
         IEnumerable<Transaction> selectedTxs = _txSource.GetTransactions(parentBlock.Header, header.GasLimit);
-        Block block = new BlockToProduce(header, selectedTxs, Array.Empty<BlockHeader>());
+        Block block = new BlockToProduce(header, selectedTxs, Array.Empty<BlockHeader>(), Enumerable.Empty<Withdrawal>());
         header.TxRoot = new TxTrie(block.Transactions).RootHash;
         block.Header.Author = _sealer.Address;
         return block;

src/Nethermind/Nethermind.Consensus/Processing/BlockExtensions.cs

@@ -26,8 +26,8 @@ internal static class BlockExtensions
     {
         public static Block CreateCopy(this Block block, BlockHeader header) =>
             block is BlockToProduce blockToProduce
-                ? new BlockToProduce(header, blockToProduce.Transactions, blockToProduce.Uncles)
-                : new Block(header, block.Transactions, block.Uncles);
+                ? new BlockToProduce(header, blockToProduce.Transactions, blockToProduce.Uncles, blockToProduce.Withdrawals)
+                : new Block(header, block.Transactions, block.Uncles, block.Withdrawals);
 
         public static IEnumerable<Transaction> GetTransactions(this Block block) =>
             block is BlockToProduce blockToProduce

src/Nethermind/Nethermind.Consensus/Processing/BlockProcessor.cs

@@ -240,6 +240,7 @@ private void ValidateProcessedBlock(Block suggestedBlock, ProcessingOptions opti
 
             block.Header.ReceiptsRoot = receipts.GetReceiptsRoot(spec, block.ReceiptsRoot);
             ApplyMinerRewards(block, blockTracer, spec);
+            ApplyWithdrawals(block, spec);
 
             _stateProvider.Commit(spec);
             _stateProvider.RecalculateStateRoot();
@@ -354,5 +355,29 @@ private void ApplyDaoTransition(Block block)
                 }
             }
         }
+
+        private void ApplyWithdrawals(Block block, IReleaseSpec spec)
+        {
+            if (!spec.IsEip4895Enabled)
+                return;
+
+            if (_logger.IsTrace) _logger.Trace($"Applying withdrawals");
+
+            foreach (var withdrawal in block.Withdrawals)
+            {
+                if (_logger.IsTrace) _logger.Trace($"  {(BigInteger)withdrawal.Amount / (BigInteger)Unit.Ether:N3}{Unit.EthSymbol} to account {withdrawal.Recipient}");
+
+                if (_stateProvider.AccountExists(withdrawal.Recipient))
+                {
+                    _stateProvider.AddToBalance(withdrawal.Recipient, withdrawal.Amount, spec);
+                }
+                else
+                {
+                    _stateProvider.CreateAccount(withdrawal.Recipient, withdrawal.Amount);
+                }
+            }
+
+            if (_logger.IsTrace) _logger.Trace($"Withdrawals applied");
+        }
     }
 }

src/Nethermind/Nethermind.Consensus/Producers/BlockProducerBase.cs

@@ -315,7 +315,7 @@ protected virtual Block PrepareBlock(BlockHeader parent, PayloadAttributes? payl
             BlockHeader header = PrepareBlockHeader(parent, payloadAttributes);
 
             IEnumerable<Transaction> transactions = GetTransactions(parent);
-            return new BlockToProduce(header, transactions, Array.Empty<BlockHeader>());
+            return new BlockToProduce(header, transactions, Array.Empty<BlockHeader>(), payloadAttributes?.Withdrawals);
         }
     }
 }

src/Nethermind/Nethermind.Consensus/Producers/BlockToProduce.cs

@@ -17,6 +17,7 @@
 
 using System;
 using System.Collections.Generic;
+using System.Linq;
 using System.Runtime.CompilerServices;
 using Nethermind.Core;
 
@@ -43,8 +44,12 @@ public new IEnumerable<Transaction> Transactions
             }
         }
 
-        public BlockToProduce(BlockHeader blockHeader, IEnumerable<Transaction> transactions, IEnumerable<BlockHeader> uncles)
-            : base(blockHeader, Array.Empty<Transaction>(), uncles)
+        public BlockToProduce(
+            BlockHeader blockHeader,
+            IEnumerable<Transaction> transactions,
+            IEnumerable<BlockHeader> uncles,
+            IEnumerable<Withdrawal>? withdrawals = null)
+            : base(blockHeader, Array.Empty<Transaction>(), uncles, withdrawals)
         {
             Transactions = transactions;
         }

src/Nethermind/Nethermind.Consensus/Producers/PayloadAttributes.cs

@@ -15,6 +15,8 @@
 //  along with the Nethermind. If not, see <http://www.gnu.org/licenses/>.
 // 
 
+using System.Collections.Generic;
+using System.Text;
 using Nethermind.Core;
 using Nethermind.Core.Crypto;
 using Nethermind.Int256;
@@ -29,6 +31,8 @@ public class PayloadAttributes
 
         public Address SuggestedFeeRecipient { get; set; }
 
+        public IList<Withdrawal>? Withdrawals { get; set; }
+
         /// <summary>
         /// GasLimit
         /// </summary>
@@ -37,9 +41,13 @@ public class PayloadAttributes
         /// </remarks>
         public long? GasLimit { get; set; }
 
-        public override string ToString()
-        {
-            return $"PayloadAttributes: ({nameof(Timestamp)}: {Timestamp}, {nameof(PrevRandao)}: {PrevRandao}, {nameof(SuggestedFeeRecipient)}: {SuggestedFeeRecipient})";
-        }
+        public override string ToString() => ToString(string.Empty);
+
+        public string ToString(string indentation) => new StringBuilder()
+            .AppendLine($"{indentation}{nameof(Timestamp)}:             {Timestamp}")
+            .AppendLine($"{indentation}{nameof(PrevRandao)}:            {PrevRandao}")
+            .AppendLine($"{indentation}{nameof(SuggestedFeeRecipient)}: {SuggestedFeeRecipient}")
+            .AppendLine($"{indentation}{nameof(Withdrawals)}:           {Withdrawals}")
+            .ToString();
     }
 }

src/Nethermind/Nethermind.Core/Block.cs

@@ -33,16 +33,17 @@ public Block(BlockHeader blockHeader, BlockBody body)
             Body = body;
         }
 
-        public Block(BlockHeader blockHeader, IEnumerable<Transaction> transactions, IEnumerable<BlockHeader> uncles)
+        public Block(
+            BlockHeader blockHeader,
+            IEnumerable<Transaction> transactions,
+            IEnumerable<BlockHeader> uncles,
+            IEnumerable<Withdrawal>? withdrawals = null)
         {
             Header = blockHeader;
-            Body = new BlockBody(transactions.ToArray(), uncles.ToArray());
+            Body = new BlockBody(transactions.ToArray(), uncles.ToArray(), withdrawals?.ToArray());
         }
 
-        public Block(BlockHeader blockHeader)
-            : this(blockHeader, BlockBody.Empty)
-        {
-        }
+        public Block(BlockHeader blockHeader) : this(blockHeader, BlockBody.Empty) { }
 
         public Block WithReplacedHeader(BlockHeader newHeader) => new(newHeader, Body);
 
@@ -60,6 +61,8 @@ public Block(BlockHeader blockHeader)
 
         public BlockHeader[] Uncles => Body.Uncles; // do not add setter here
 
+        public Withdrawal[]? Withdrawals => Body.Withdrawals;
+
         public Keccak? Hash => Header.Hash; // do not add setter here
 
         public Keccak? ParentHash => Header.ParentHash; // do not add setter here
@@ -130,18 +133,25 @@ private string ToFullString()
             StringBuilder builder = new();
             builder.AppendLine($"Block {Number}");
             builder.AppendLine("  Header:");
-            builder.Append($"{Header.ToString("    ")}");
+            builder.Append(Header.ToString("    "));
 
             builder.AppendLine("  Uncles:");
             foreach (BlockHeader uncle in Body.Uncles ?? Array.Empty<BlockHeader>())
             {
-                builder.Append($"{uncle.ToString("    ")}");
+                builder.Append(uncle.ToString("    "));
             }
 
             builder.AppendLine("  Transactions:");
             foreach (Transaction tx in Body?.Transactions ?? Array.Empty<Transaction>())
             {
-                builder.Append($"{tx.ToString("    ")}");
+                builder.Append(tx.ToString("    "));
+            }
+
+            builder.AppendLine("  Withdrawals:");
+
+            foreach (var w in Body?.Withdrawals ?? Array.Empty<Withdrawal>())
+            {
+                builder.Append(w.ToString("    "));
             }
 
             return builder.ToString();

src/Nethermind/Nethermind.Core/BlockBody.cs

@@ -20,37 +20,31 @@ namespace Nethermind.Core
 {
     public class BlockBody
     {
-        public BlockBody(Transaction[]? transactions, BlockHeader[]? uncles)
+        public BlockBody(Transaction[]? transactions, BlockHeader[]? uncles, Withdrawal[]? withdrawals = null)
         {
             Transactions = transactions ?? Array.Empty<Transaction>();
             Uncles = uncles ?? Array.Empty<BlockHeader>();
+            Withdrawals = withdrawals;
         }
 
-        public BlockBody()
-            : this(null, null)
-        {
-        }
+        public BlockBody() : this(null, null, null) { }
 
-        public BlockBody WithChangedTransactions(Transaction[] transactions)
-        {
-            return new(transactions, Uncles);
-        }
+        public BlockBody WithChangedTransactions(Transaction[] transactions) => new(transactions, Uncles, Withdrawals);
 
-        public BlockBody WithChangedUncles(BlockHeader[] uncles)
-        {
-            return new(Transactions, uncles);
-        }
+        public BlockBody WithChangedUncles(BlockHeader[] uncles) => new(Transactions, uncles, Withdrawals);
 
-        public static BlockBody WithOneTransactionOnly(Transaction tx)
-        {
-            return new(new[] { tx }, Array.Empty<BlockHeader>());
-        }
+        public BlockBody WithChangedWithdrawals(Withdrawal[]? withdrawals) => new(Transactions, Uncles, withdrawals);
+
+        public static BlockBody WithOneTransactionOnly(Transaction tx) => new(new[] { tx }, null, null);
 
         public Transaction[] Transactions { get; internal set; }
+
         public BlockHeader[] Uncles { get; }
 
-        public static readonly BlockBody Empty = new();
+        public Withdrawal[]? Withdrawals { get; internal set; }
+
+        public static BlockBody Empty { get; } = new();
 
-        public bool IsEmpty => Transactions.Length == 0 && Uncles.Length == 0;
+        public bool IsEmpty => Transactions.Length == 0 && Uncles.Length == 0 && (Withdrawals?.Length ?? 0) == 0;
     }
 }

src/Nethermind/Nethermind.Core/BlockHeader.cs

@@ -59,6 +59,7 @@ public class BlockHeader
         public Address? GasBeneficiary => Author ?? Beneficiary;
         public Keccak? StateRoot { get; set; }
         public Keccak? TxRoot { get; set; }
+        public Keccak? WithdrawalsRoot { get; set; }
         public Keccak? ReceiptsRoot { get; set; }
         public Bloom? Bloom { get; set; }
         public UInt256 Difficulty { get; set; }
@@ -99,6 +100,7 @@ public string ToString(string indent)
             builder.AppendLine($"{indent}Nonce: {Nonce}");
             builder.AppendLine($"{indent}Uncles Hash: {UnclesHash}");
             builder.AppendLine($"{indent}Tx Root: {TxRoot}");
+            builder.AppendLine($"{indent}Withdrawals Root: {WithdrawalsRoot}");
             builder.AppendLine($"{indent}Receipts Root: {ReceiptsRoot}");
             builder.AppendLine($"{indent}State Root: {StateRoot}");
             builder.AppendLine($"{indent}BaseFeePerGas: {BaseFeePerGas}");
@@ -108,23 +110,14 @@ public string ToString(string indent)
             return builder.ToString();
         }
 
-        public override string ToString()
-        {
-            return ToString(string.Empty);
-        }
+        public override string ToString() => ToString(string.Empty);
 
-        public string ToString(Format format)
+        public string ToString(Format format) => format switch
         {
-            switch (format)
-            {
-                case Format.Full:
-                    return ToString(string.Empty);
-                case Format.FullHashAndNumber:
-                    return Hash == null ? $"{Number} null" : $"{Number} ({Hash})";
-                default:
-                    return Hash == null ? $"{Number} null" : $"{Number} ({Hash.ToShortString()})";
-            }
-        }
+            Format.Full => ToString(string.Empty),
+            Format.FullHashAndNumber => Hash == null ? $"{Number} null" : $"{Number} ({Hash})",
+            _ => Hash == null ? $"{Number} null" : $"{Number} ({Hash.ToShortString()})",
+        };
 
         [Todo(Improve.Refactor, "Use IFormattable here")]
         public enum Format

src/Nethermind/Nethermind.Core/Specs/IReleaseSpec.cs

@@ -1,16 +1,16 @@
 //  Copyright (c) 2021 Demerzel Solutions Limited
 //  This file is part of the Nethermind library.
-// 
+//
 //  The Nethermind library is free software: you can redistribute it and/or modify
 //  it under the terms of the GNU Lesser General Public License as published by
 //  the Free Software Foundation, either version 3 of the License, or
 //  (at your option) any later version.
-// 
+//
 //  The Nethermind library is distributed in the hope that it will be useful,
 //  but WITHOUT ANY WARRANTY; without even the implied warranty of
 //  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
 //  GNU Lesser General Public License for more details.
-// 
+//
 //  You should have received a copy of the GNU Lesser General Public License
 //  along with the Nethermind. If not, see <http://www.gnu.org/licenses/>.
 
@@ -241,7 +241,7 @@ public interface IReleaseSpec
         bool IsEip3529Enabled { get; }
 
         /// <summary>
-        /// Reject new contracts starting with the 0xEF byte 
+        /// Reject new contracts starting with the 0xEF byte
         /// </summary>
         bool IsEip3541Enabled { get; }
 
@@ -271,6 +271,13 @@ public interface IReleaseSpec
         /// </summary>
         bool IsEip3855Enabled { get; }
 
+        /// <summary>
+        /// Gets or sets a value indicating whether the
+        /// <see href="https://eips.ethereum.org/EIPS/eip-4895">EIP-4895</see>
+        /// validator withdrawals are enabled.
+        /// </summary>
+        bool IsEip4895Enabled { get; }
+
         /// <summary>
         /// Should transactions be validated against chainId.
         /// </summary>
@@ -285,7 +292,9 @@ public interface IReleaseSpec
 
         public long Eip1559TransitionBlock { get; }
 
-        // STATE related 
+        public ulong WithdrawalTimestamp { get; }
+
+        // STATE related
         public bool ClearEmptyAccountWhenTouched => IsEip158Enabled;
 
         // VM

src/Nethermind/Nethermind.Core/Withdrawal.cs

@@ -0,0 +1,39 @@
+using System.Text;
+using Nethermind.Int256;
+
+namespace Nethermind.Core;
+
+/// <summary>
+/// Represents a withdrawal that has been validated at the consensus layer.
+/// </summary>
+public class Withdrawal
+{
+    /// <summary>
+    /// Gets or sets the withdrawal amount as a big-endian value in units of Wei.
+    /// </summary>
+    public UInt256 Amount { get; set; }
+
+    /// <summary>
+    /// Gets or sets the withdrawal unique id.
+    /// </summary>
+    public ulong Index { get; set; }
+
+    /// <summary>
+    /// Gets or sets the withdrawal recipient address.
+    /// </summary>
+    public Address Recipient { get; set; } = Address.Zero;
+
+    /// <summary>
+    /// Gets or sets the validator index on the consensus layer the withdrawal corresponds to.
+    /// </summary>
+    public ulong ValidatorIndex { get; set; }
+
+    public override string ToString() => ToString(string.Empty);
+
+    public string ToString(string indentation) => new StringBuilder()
+        .AppendLine($"{indentation}{nameof(Index)}:          {Index}")
+        .AppendLine($"{indentation}{nameof(ValidatorIndex)}: {ValidatorIndex}")
+        .AppendLine($"{indentation}{nameof(Recipient)}:      {Recipient}")
+        .AppendLine($"{indentation}{nameof(Amount)}:         {Amount}")
+        .ToString();
+}