Skip to content

Commit

Permalink
Use ExtensiblePayload in consensus (#2202)
Browse files Browse the repository at this point in the history
  • Loading branch information
@erikzhang
erikzhang committed Jan 10, 2021
1 parent dfb56a2 commit a9fe75d
Show file tree
Hide file tree
Showing 27 changed files with 359 additions and 440 deletions.
147 changes: 110 additions & 37 deletions src/neo/Consensus/ConsensusContext.cs
View file
Original file line number Diff line number Diff line change
Expand Up @@ -13,6 +13,7 @@
using System.IO;
using System.Linq;
using System.Runtime.CompilerServices;
using static Neo.Consensus.RecoveryMessage;

namespace Neo.Consensus
{
Expand All @@ -29,10 +30,10 @@ public class ConsensusContext : IDisposable, ISerializable
public int MyIndex;
public UInt256[] TransactionHashes;
public Dictionary<UInt256, Transaction> Transactions;
public ConsensusPayload[] PreparationPayloads;
public ConsensusPayload[] CommitPayloads;
public ConsensusPayload[] ChangeViewPayloads;
public ConsensusPayload[] LastChangeViewPayloads;
public ExtensiblePayload[] PreparationPayloads;
public ExtensiblePayload[] CommitPayloads;
public ExtensiblePayload[] ChangeViewPayloads;
public ExtensiblePayload[] LastChangeViewPayloads;
// LastSeenMessage array stores the height of the last seen message, for each validator.
// if this node never heard from validator i, LastSeenMessage[i] will be -1.
public Dictionary<ECPoint, uint> LastSeenMessage { get; private set; }
Expand All @@ -47,6 +48,7 @@ public class ConsensusContext : IDisposable, ISerializable
private int _witnessSize;
private readonly Wallet wallet;
private readonly IStore store;
private Dictionary<UInt256, ConsensusMessage> cachedMessages;

public int F => (Validators.Length - 1) / 3;
public int M => Validators.Length - F;
Expand Down Expand Up @@ -79,7 +81,7 @@ public bool ValidatorsChanged
public bool ResponseSent => !WatchOnly && PreparationPayloads[MyIndex] != null;
public bool CommitSent => !WatchOnly && CommitPayloads[MyIndex] != null;
public bool BlockSent => Block.Transactions != null;
public bool ViewChanging => !WatchOnly && ChangeViewPayloads[MyIndex]?.GetDeserializedMessage<ChangeView>().NewViewNumber > ViewNumber;
public bool ViewChanging => !WatchOnly && GetMessage<ChangeView>(ChangeViewPayloads[MyIndex])?.NewViewNumber > ViewNumber;
public bool NotAcceptingPayloadsDueToViewChanging => ViewChanging && !MoreThanFNodesCommittedOrLost;
// A possible attack can happen if the last node to commit is malicious and either sends change view after his
// commit to stall nodes in a higher view, or if he refuses to send recovery messages. In addition, if a node
Expand All @@ -104,15 +106,34 @@ public Block CreateBlock()
ContractParametersContext sc = new ContractParametersContext(Block);
for (int i = 0, j = 0; i < Validators.Length && j < M; i++)
{
if (CommitPayloads[i]?.ConsensusMessage.ViewNumber != ViewNumber) continue;
sc.AddSignature(contract, Validators[i], CommitPayloads[i].GetDeserializedMessage<Commit>().Signature);
if (GetMessage(CommitPayloads[i])?.ViewNumber != ViewNumber) continue;
sc.AddSignature(contract, Validators[i], GetMessage<Commit>(CommitPayloads[i]).Signature);
j++;
}
Block.Witness = sc.GetWitnesses()[0];
Block.Transactions = TransactionHashes.Select(p => Transactions[p]).ToArray();
return Block;
}

public ExtensiblePayload CreatePayload(ConsensusMessage message, byte[] invocationScript = null)
{
ExtensiblePayload payload = new ExtensiblePayload
{
Category = "Consensus",
ValidBlockStart = 0,
ValidBlockEnd = message.BlockIndex,
Sender = GetSender(message.ValidatorIndex),
Data = message.ToArray(),
Witness = invocationScript is null ? null : new Witness
{
InvocationScript = invocationScript,
VerificationScript = Contract.CreateSignatureRedeemScript(Validators[message.ValidatorIndex])
}
};
cachedMessages.TryAdd(payload.Hash, message);
return payload;
}

public void Deserialize(BinaryReader reader)
{
Reset(0);
Expand All @@ -126,10 +147,10 @@ public void Deserialize(BinaryReader reader)
ViewNumber = reader.ReadByte();
TransactionHashes = reader.ReadSerializableArray<UInt256>();
Transaction[] transactions = reader.ReadSerializableArray<Transaction>(Block.MaxTransactionsPerBlock);
PreparationPayloads = reader.ReadNullableArray<ConsensusPayload>(ProtocolSettings.Default.ValidatorsCount);
CommitPayloads = reader.ReadNullableArray<ConsensusPayload>(ProtocolSettings.Default.ValidatorsCount);
ChangeViewPayloads = reader.ReadNullableArray<ConsensusPayload>(ProtocolSettings.Default.ValidatorsCount);
LastChangeViewPayloads = reader.ReadNullableArray<ConsensusPayload>(ProtocolSettings.Default.ValidatorsCount);
PreparationPayloads = reader.ReadNullableArray<ExtensiblePayload>(ProtocolSettings.Default.ValidatorsCount);
CommitPayloads = reader.ReadNullableArray<ExtensiblePayload>(ProtocolSettings.Default.ValidatorsCount);
ChangeViewPayloads = reader.ReadNullableArray<ExtensiblePayload>(ProtocolSettings.Default.ValidatorsCount);
LastChangeViewPayloads = reader.ReadNullableArray<ExtensiblePayload>(ProtocolSettings.Default.ValidatorsCount);
if (TransactionHashes.Length == 0 && !RequestSentOrReceived)
TransactionHashes = null;
Transactions = transactions.Length == 0 && !RequestSentOrReceived ? null : transactions.ToDictionary(p => p.Hash);
Expand All @@ -154,13 +175,64 @@ public Block EnsureHeader()
return Block;
}

public ConsensusMessage GetMessage(ExtensiblePayload payload)
{
if (payload is null) return null;
if (!cachedMessages.TryGetValue(payload.Hash, out ConsensusMessage message))
cachedMessages.Add(payload.Hash, message = ConsensusMessage.DeserializeFrom(payload.Data));
return message;
}

public T GetMessage<T>(ExtensiblePayload payload) where T : ConsensusMessage
{
return (T)GetMessage(payload);
}

private ChangeViewPayloadCompact GetChangeViewPayloadCompact(ExtensiblePayload payload)
{
ChangeView message = GetMessage<ChangeView>(payload);
return new ChangeViewPayloadCompact
{
ValidatorIndex = message.ValidatorIndex,
OriginalViewNumber = message.ViewNumber,
Timestamp = message.Timestamp,
InvocationScript = payload.Witness.InvocationScript
};
}

private CommitPayloadCompact GetCommitPayloadCompact(ExtensiblePayload payload)
{
Commit message = GetMessage<Commit>(payload);
return new CommitPayloadCompact
{
ViewNumber = message.ViewNumber,
ValidatorIndex = message.ValidatorIndex,
Signature = message.Signature,
InvocationScript = payload.Witness.InvocationScript
};
}

private PreparationPayloadCompact GetPreparationPayloadCompact(ExtensiblePayload payload)
{
return new PreparationPayloadCompact
{
ValidatorIndex = GetMessage(payload).ValidatorIndex,
InvocationScript = payload.Witness.InvocationScript
};
}

[MethodImpl(MethodImplOptions.AggressiveInlining)]
public byte GetPrimaryIndex(byte viewNumber)
{
int p = ((int)Block.Index - viewNumber) % Validators.Length;
return p >= 0 ? (byte)p : (byte)(p + Validators.Length);
}

public UInt160 GetSender(int index)
{
return Contract.CreateSignatureRedeemScript(Validators[index]).ToScriptHash();
}

public bool Load()
{
byte[] data = store.TryGet(ConsensusStatePrefix, null);
Expand All @@ -180,7 +252,7 @@ public bool Load()
}
}

public ConsensusPayload MakeChangeView(ChangeViewReason reason)
public ExtensiblePayload MakeChangeView(ChangeViewReason reason)
{
return ChangeViewPayloads[MyIndex] = MakeSignedPayload(new ChangeView
{
Expand All @@ -189,30 +261,25 @@ public ConsensusPayload MakeChangeView(ChangeViewReason reason)
});
}

public ConsensusPayload MakeCommit()
public ExtensiblePayload MakeCommit()
{
return CommitPayloads[MyIndex] ?? (CommitPayloads[MyIndex] = MakeSignedPayload(new Commit
{
Signature = EnsureHeader().Sign(keyPair)
}));
}

private ConsensusPayload MakeSignedPayload(ConsensusMessage message)
private ExtensiblePayload MakeSignedPayload(ConsensusMessage message)
{
message.BlockIndex = Block.Index;
message.ValidatorIndex = (byte)MyIndex;
message.ViewNumber = ViewNumber;
ConsensusPayload payload = new ConsensusPayload
{
Version = Block.Version,
PrevHash = Block.PrevHash,
BlockIndex = Block.Index,
ValidatorIndex = (byte)MyIndex,
ConsensusMessage = message
};
ExtensiblePayload payload = CreatePayload(message, null);
SignPayload(payload);
return payload;
}

private void SignPayload(ConsensusPayload payload)
private void SignPayload(ExtensiblePayload payload)
{
ContractParametersContext sc;
try
Expand Down Expand Up @@ -308,7 +375,7 @@ internal void EnsureMaxBlockLimitation(IEnumerable<Transaction> txs)
TransactionHashes = hashes.ToArray();
}

public ConsensusPayload MakePrepareRequest()
public ExtensiblePayload MakePrepareRequest()
{
var random = new Random();
Span<byte> buffer = stackalloc byte[sizeof(ulong)];
Expand All @@ -319,47 +386,52 @@ public ConsensusPayload MakePrepareRequest()

return PreparationPayloads[MyIndex] = MakeSignedPayload(new PrepareRequest
{
Version = Block.Version,
PrevHash = Block.PrevHash,
Timestamp = Block.Timestamp,
Nonce = Block.ConsensusData.Nonce,
TransactionHashes = TransactionHashes
});
}

public ConsensusPayload MakeRecoveryRequest()
public ExtensiblePayload MakeRecoveryRequest()
{
return MakeSignedPayload(new RecoveryRequest
{
Timestamp = TimeProvider.Current.UtcNow.ToTimestampMS()
});
}

public ConsensusPayload MakeRecoveryMessage()
public ExtensiblePayload MakeRecoveryMessage()
{
PrepareRequest prepareRequestMessage = null;
if (TransactionHashes != null)
{
prepareRequestMessage = new PrepareRequest
{
Version = Block.Version,
PrevHash = Block.PrevHash,
ViewNumber = ViewNumber,
Timestamp = Block.Timestamp,
BlockIndex = Block.Index,
Nonce = Block.ConsensusData.Nonce,
TransactionHashes = TransactionHashes
};
}
return MakeSignedPayload(new RecoveryMessage()
{
ChangeViewMessages = LastChangeViewPayloads.Where(p => p != null).Select(p => RecoveryMessage.ChangeViewPayloadCompact.FromPayload(p)).Take(M).ToDictionary(p => (int)p.ValidatorIndex),
ChangeViewMessages = LastChangeViewPayloads.Where(p => p != null).Select(p => GetChangeViewPayloadCompact(p)).Take(M).ToDictionary(p => (int)p.ValidatorIndex),
PrepareRequestMessage = prepareRequestMessage,
// We only need a PreparationHash set if we don't have the PrepareRequest information.
PreparationHash = TransactionHashes == null ? PreparationPayloads.Where(p => p != null).GroupBy(p => p.GetDeserializedMessage<PrepareResponse>().PreparationHash, (k, g) => new { Hash = k, Count = g.Count() }).OrderByDescending(p => p.Count).Select(p => p.Hash).FirstOrDefault() : null,
PreparationMessages = PreparationPayloads.Where(p => p != null).Select(p => RecoveryMessage.PreparationPayloadCompact.FromPayload(p)).ToDictionary(p => (int)p.ValidatorIndex),
PreparationHash = TransactionHashes == null ? PreparationPayloads.Where(p => p != null).GroupBy(p => GetMessage<PrepareResponse>(p).PreparationHash, (k, g) => new { Hash = k, Count = g.Count() }).OrderByDescending(p => p.Count).Select(p => p.Hash).FirstOrDefault() : null,
PreparationMessages = PreparationPayloads.Where(p => p != null).Select(p => GetPreparationPayloadCompact(p)).ToDictionary(p => (int)p.ValidatorIndex),
CommitMessages = CommitSent
? CommitPayloads.Where(p => p != null).Select(p => RecoveryMessage.CommitPayloadCompact.FromPayload(p)).ToDictionary(p => (int)p.ValidatorIndex)
: new Dictionary<int, RecoveryMessage.CommitPayloadCompact>()
? CommitPayloads.Where(p => p != null).Select(p => GetCommitPayloadCompact(p)).ToDictionary(p => (int)p.ValidatorIndex)
: new Dictionary<int, CommitPayloadCompact>()
});
}

public ConsensusPayload MakePrepareResponse()
public ExtensiblePayload MakePrepareResponse()
{
return PreparationPayloads[MyIndex] = MakeSignedPayload(new PrepareResponse
{
Expand Down Expand Up @@ -401,9 +473,9 @@ public void Reset(byte viewNumber)
}
}
MyIndex = -1;
ChangeViewPayloads = new ConsensusPayload[Validators.Length];
LastChangeViewPayloads = new ConsensusPayload[Validators.Length];
CommitPayloads = new ConsensusPayload[Validators.Length];
ChangeViewPayloads = new ExtensiblePayload[Validators.Length];
LastChangeViewPayloads = new ExtensiblePayload[Validators.Length];
CommitPayloads = new ExtensiblePayload[Validators.Length];
if (ValidatorsChanged || LastSeenMessage is null)
{
var previous_last_seen_message = LastSeenMessage;
Expand All @@ -425,11 +497,12 @@ public void Reset(byte viewNumber)
keyPair = account.GetKey();
break;
}
cachedMessages = new Dictionary<UInt256, ConsensusMessage>();
}
else
{
for (int i = 0; i < LastChangeViewPayloads.Length; i++)
if (ChangeViewPayloads[i]?.GetDeserializedMessage<ChangeView>().NewViewNumber >= viewNumber)
if (GetMessage<ChangeView>(ChangeViewPayloads[i])?.NewViewNumber >= viewNumber)
LastChangeViewPayloads[i] = ChangeViewPayloads[i];
else
LastChangeViewPayloads[i] = null;
Expand All @@ -443,7 +516,7 @@ public void Reset(byte viewNumber)
Block.Timestamp = 0;
Block.Transactions = null;
TransactionHashes = null;
PreparationPayloads = new ConsensusPayload[Validators.Length];
PreparationPayloads = new ExtensiblePayload[Validators.Length];
if (MyIndex >= 0) LastSeenMessage[Validators[MyIndex]] = Block.Index;
}

Expand Down
14 changes: 13 additions & 1 deletion src/neo/Consensus/ConsensusMessage.cs
View file
Original file line number Diff line number Diff line change
Expand Up @@ -8,9 +8,15 @@ namespace Neo.Consensus
public abstract class ConsensusMessage : ISerializable
{
public readonly ConsensusMessageType Type;
public uint BlockIndex;
public byte ValidatorIndex;
public byte ViewNumber;

public virtual int Size => sizeof(ConsensusMessageType) + sizeof(byte);
public virtual int Size =>
sizeof(ConsensusMessageType) + //Type
sizeof(uint) + //BlockIndex
sizeof(byte) + //ValidatorIndex
sizeof(byte); //ViewNumber

protected ConsensusMessage(ConsensusMessageType type)
{
Expand All @@ -23,6 +29,10 @@ public virtual void Deserialize(BinaryReader reader)
{
if (Type != (ConsensusMessageType)reader.ReadByte())
throw new FormatException();
BlockIndex = reader.ReadUInt32();
ValidatorIndex = reader.ReadByte();
if (ValidatorIndex >= ProtocolSettings.Default.ValidatorsCount)
throw new FormatException();
ViewNumber = reader.ReadByte();
}

Expand All @@ -37,6 +47,8 @@ public static ConsensusMessage DeserializeFrom(byte[] data)
public virtual void Serialize(BinaryWriter writer)
{
writer.Write((byte)Type);
writer.Write(BlockIndex);
writer.Write(ValidatorIndex);
writer.Write(ViewNumber);
}
}
Expand Down
Loading

0 comments on commit a9fe75d

Please sign in to comment.