public async ValueTask AttachAsync(IPeerContext peerContext)
{
PeerContext = peerContext as ExamplePeerContext ?? throw new ArgumentException("Expected ExamplePeerContext", nameof(peerContext));
_messageWriter = PeerContext.GetMessageWriter();
await OnPeerAttachedAsync().ConfigureAwait(false);
}
public PrepareExtensionProtocolHandshakeContext(BDictionary handshakeContent,
IPeerContext peerContext,
Action <IExtensionProtocolMessage> sendMessage)
: base(peerContext, sendMessage)
{
HandshakeContent = handshakeContent;
}
/// <summary>
/// Check if the client is allowed to connect based on certain criteria.
/// </summary>
/// <returns>When criteria is met returns <c>true</c>, to allow connection.</returns>
private bool EnsurePeerCanConnect(ConnectionContext connection, IPeerContext peerContext)
{
if (_serverPeerConnectionGuards == null)
{
return(false);
}
ServerPeerConnectionGuardResult?result = (
from guard in _serverPeerConnectionGuards
let guardResult = guard.Check(peerContext)
where guardResult.IsDenied
select guardResult
)
.DefaultIfEmpty(ServerPeerConnectionGuardResult.Success)
.FirstOrDefault();
if (result == null)
{
return(true); // no guards
}
if (result.IsDenied)
{
_logger.LogDebug("Connection from client '{ConnectingPeerEndPoint}' was rejected because of {ClientDisconnectedReason} and will be closed.", connection.RemoteEndPoint, result.DenyReason);
connection.Abort(new ConnectionAbortedException(result.DenyReason));
_eventBus.Publish(new PeerConnectionRejected(peerContext, result.DenyReason));
return(false);
}
return(true);
}
public void SetPeerContext(IPeerContext peerContext)
{
_networkPeerContext = peerContext as NetworkPeerContext ?? throw new ArgumentException("Expected NetworkPeerContext", nameof(peerContext));;
_deserializationContext.SetInitiator(_networkPeerContext.Direction == PeerConnectionDirection.Outbound);
LightningEndpoint?lightningEndpoint = null;
if (peerContext.Direction == PeerConnectionDirection.Outbound)
{
OutgoingConnectionEndPoint endpoint = peerContext.Features.Get <OutgoingConnectionEndPoint>();
if (endpoint == null || !endpoint.Items.TryGetValue(nameof(LightningEndpoint), out object?res))
{
_logger.LogError("Remote connection was not found ");
throw new ApplicationException("Initiator connection must have a public key of the remote node");
}
if (res == null)
{
_logger.LogError("Remote connection type is invalid");
throw new ApplicationException("Remote connection type is invalid");
}
lightningEndpoint = (LightningEndpoint)res;
}
_handshakeProtocol = new HandshakeWithNoiseProtocol(_nodeContext, lightningEndpoint?.NodePubKey, _handshakeProcessor);
_networkPeerContext.SetHandshakeProtocol(_handshakeProtocol);
}
public ExtensionProtocolMessageReceivedContext(IExtensionProtocolMessage message,
IPeerContext peerContext,
Action <IExtensionProtocolMessage> sendMessage)
: base(peerContext, sendMessage)
{
Message = message;
}
public virtual IPeerContext CreateOutgoingPeerContext(string peerId, EndPoint localEndPoint, OutgoingConnectionEndPoint outgoingConnectionEndPoint, INetworkMessageWriter messageWriter)
{
IPeerContext peerContext = Create(PeerConnectionDirection.Outbound, peerId, localEndPoint, outgoingConnectionEndPoint.EndPoint, messageWriter);
peerContext.Features.Set(outgoingConnectionEndPoint);
return(peerContext);
}
public override async Task OnConnectedAsync(ConnectionContext connection)
{
if (connection is null)
{
throw new ArgumentNullException(nameof(connection));
}
using IDisposable loggerScope = _logger.BeginScope("Peer {PeerId} connected to server {ServerEndpoint}", connection.ConnectionId, connection.LocalEndPoint);
ProtocolReader reader = connection.CreateReader();
INetworkProtocolMessageSerializer protocol = _serviceProvider.GetRequiredService <INetworkProtocolMessageSerializer>();
using IPeerContext peerContext = _peerContextFactory.CreateIncomingPeerContext(connection.ConnectionId,
connection.LocalEndPoint !.AsIPEndPoint().EnsureIPv6(),
connection.RemoteEndPoint !.AsIPEndPoint().EnsureIPv6(),
new NetworkMessageWriter(protocol, connection.CreateWriter()));
using CancellationTokenRegistration cancellationRegistration = peerContext.ConnectionCancellationTokenSource.Token.Register(() =>
{
connection.Abort(new ConnectionAbortedException("Requested by PeerContext"));
});
connection.Features.Set(peerContext);
protocol.SetPeerContext(peerContext);
if (EnsurePeerCanConnect(connection, peerContext))
{
_eventBus.Publish(new PeerConnected(peerContext));
await _networkMessageProcessorFactory.StartProcessorsAsync(peerContext).ConfigureAwait(false);
while (true)
{
try
{
ProtocolReadResult <INetworkMessage> result = await reader.ReadAsync(protocol).ConfigureAwait(false);
if (result.IsCompleted)
{
break;
}
await ProcessMessageAsync(result.Message, peerContext, connection.ConnectionClosed).ConfigureAwait(false);
}
catch (Exception ex)
{
_logger.LogDebug(ex, "Unexpected connection terminated because of {DisconnectionReason}.", ex.Message);
break;
}
finally
{
reader.Advance();
}
}
return;
}
}
internal override string?TryGetDenyReason(IPeerContext peerContext)
{
if (_peerAddressBook.IsBanned(peerContext))
{
return("Inbound connection refused: peer is banned.");
}
return(null);
}
public void OnPeerConnected(IPeerContext context)
{
foreach (var messageId in MessageIds)
{
context.RegisterMessageHandler(messageId);
}
context.Peer.SendMessage(new BitfieldMessage(new Bitfield(context.Metainfo.Pieces.Count, context.DataHandler.CompletedPieces)));
}
internal override string?TryGetDenyReason(IPeerContext peerContext)
{
if (!settings.AllowLoopbackConnection && IPAddress.IsLoopback(peerContext.RemoteEndPoint.Address))
{
return($"Loopback peer connection not allowed (set {nameof(settings.AllowLoopbackConnection)} to true to allow such kind of connections).");
}
return(null);
}
internal override string TryGetDenyReason(IPeerContext peerContext)
{
if (this.serverPeerStats.ConnectedInboundPeersCount >= this.settings.MaxInboundConnections)
{
return("Inbound connection refused: max connection threshold reached.");
}
return(null);
}
public BitcoinNetworkProtocolMessageSerializer(ILogger <BitcoinNetworkProtocolMessageSerializer> logger, INetworkDefinition chainDefinition, INetworkMessageSerializerManager networkMessageSerializerManager)
{
_logger = logger;
_chainDefinition = chainDefinition;
_networkMessageSerializerManager = networkMessageSerializerManager;
_deserializationContext = new DeserializationContext(chainDefinition.MagicBytes);
_peerContext = null !; //initialized by SetPeerContext
}
public void Serialize(INetworkMessage message, int protocolVersion, IPeerContext peerContext, IBufferWriter <byte> output)
{
if (message is null)
{
throw new ArgumentNullException(nameof(message));
}
Serialize((TMessageType)message, protocolVersion, (TPeerContext)peerContext, output);
}
private void SendMessage(IPeerContext peerContext, Action <BinaryWriter> constructMessage)
{
using (var ms = new MemoryStream())
{
BinaryWriter writer = new BigEndianBinaryWriter(ms);
constructMessage(writer);
writer.Flush();
peerContext.SendMessage(ExtensionProtocolMessageId, ms.ToArray());
}
}
internal override string?TryGetDenyReason(IPeerContext peerContext)
{
//TODO implement ban check, bitcoin core ref: https://github.com/bitcoin/bitcoin/blob/e8e79958a7b2a0bf1b02adcce9f4d811eac37dfc/src/net.cpp#L984-L993
//if (peer is banned)
//{
// return "Current peer is banned.";
//}
return(null);
}
public bool TrySerialize(INetworkMessage message, int protocolVersion, IPeerContext peerContext, IBufferWriter <byte> output)
{
if (_serializers.TryGetValue(message.Command, out INetworkMessageSerializer? serializer))
{
serializer.Serialize(message, protocolVersion, peerContext, output);
return(true);
}
return(false);
}
public void SetPeerContext(IPeerContext peerContext)
{
// we know it's an ExamplePeerContext in our example.
_peerContext = (ExamplePeerContext)peerContext;
if (_peerContext.MyExtraInformation != null)
{
_logger.LogDebug("I'm ExampleNetworkProtocolMessageSerializer and I know that I've some information for you: {AdditionalInformation}", _peerContext.MyExtraInformation);
}
}
private async Task ProcessMessageAsync(INetworkMessage message, IPeerContext peerContext, CancellationToken cancellation)
{
using IDisposable logScope = _logger.BeginScope("Processing message '{Command}'", message.Command);
if (!(message is UnknownMessage))
{
await _networkMessageProcessorFactory.ProcessMessageAsync(message, peerContext, cancellation).ConfigureAwait(false);
_eventBus.Publish(new PeerMessageReceived(peerContext, message));
}
}
public int GetScore(IPeerContext peerContext)
{
if (!_connectedPeers.TryGetValue(peerContext.PeerId, out PeerScore? score))
{
_logger.LogWarning("Peer {PeerId} not found, returning neutral score.", peerContext.PeerId);
return(0);
}
else
{
return(score.Score);
}
}
public void AddBonus(IPeerContext peerContext, uint bonus, string reason)
{
if (!_connectedPeers.TryGetValue(peerContext.PeerId, out PeerScore? score))
{
_logger.LogWarning("Cannot attribute positive points to the peer {PeerId} because the peer isn't connected.", peerContext.PeerId);
}
else
{
_logger.LogDebug("Peer {PeerId} got a bonus {PeerBonus}: {MisbehaveReason}.", peerContext.PeerId, bonus, reason);
score.UpdateScore((int)bonus);
}
}
public ServerPeerConnectionGuardResult Check(IPeerContext peerContext)
{
string denyReason = this.TryGetDenyReason(peerContext);
if (!string.IsNullOrEmpty(denyReason))
{
this.logger.LogDebug("Peer connection guard not passed: {denyReason}", denyReason);
return(ServerPeerConnectionGuardResult.Deny(denyReason));
}
return(ServerPeerConnectionGuardResult.Allow());
}
internal override string?TryGetDenyReason(IPeerContext peerContext)
{
if (_peerStats.ConnectedInboundPeersCount >= settings.MaxInboundConnections)
{
/// TODO: try to evict eventual bad connection to let a space for this connection
/// ref: https://github.com/bitcoin/bitcoin/blob/e8e79958a7b2a0bf1b02adcce9f4d811eac37dfc/src/net.cpp#L995-L1003
/// I'd consider another approach: accept a connection that exceed the maximum allowed connection, try to handshake
/// and if successful then decide either if evict one connect and keep this, or drop the connection attempt
return("Inbound connection refused: max connection threshold reached.");
}
return(null);
}
private void SendExtensionMessage(IPeerContext peerContext, IExtensionProtocolMessage message)
{
var peerMessageIds = peerContext.GetValue <Dictionary <string, byte> >(ExtensionProtocolMessageIds);
if (!peerMessageIds.TryGetValue(message.MessageType, out byte messageType))
{
throw new InvalidOperationException($"Peer does not support message type {message.MessageType}");
}
SendMessage(peerContext, writer =>
{
writer.Write(messageType);
writer.Write(message.Serialize());
});
}
internal override string?TryGetDenyReason(IPeerContext peerContext)
{
if (_initialBlockDownloadState.IsDownloadingBlocks())
{
bool clientIsWhiteListed = settings.Listeners
.Any(binding => binding.IsWhitelistingEndpoint && binding.Matches(peerContext.LocalEndPoint));
if (!clientIsWhiteListed)
{
return("Node is in IBD and the peer is not white-listed.");
}
}
return(null);
}
void IModule.OnPeerConnected(IPeerContext context)
{
// Check for extension protocol support
bool supportsExtensionProtocol = (context.Peer.ReservedBytes[5] & 0x10) != 0;
if (!supportsExtensionProtocol)
{
return;
}
// Register to receive extension protocol messages
context.RegisterMessageHandler(ExtensionProtocolMessageId);
// Send handshake message
var handshake = new ExtensionProtocolHandshake
{
MessageIds = _supportedMessages,
Client = "TorrentCore 0.1", // todo
};
var handshakeDict = handshake.Serialize();
var prepareHandshakeContext =
new PrepareExtensionProtocolHandshakeContext(
handshakeDict,
context,
msg => SendExtensionMessage(context, msg));
foreach (var handler in _registeredHandlers)
{
handler.PrepareExtensionProtocolHandshake(prepareHandshakeContext);
}
SendMessage(context, writer =>
{
writer.Write((byte)0);
writer.Flush();
handshakeDict.EncodeTo(writer.BaseStream);
});
}
/// <summary>
/// Attaches known processors to specified peer.
/// </summary>
/// <param name="peerContext">The peer context.</param>
public async Task StartProcessorsAsync(IPeerContext peerContext)
{
if (peerContext is null)
{
ThrowHelper.ThrowArgumentNullException(nameof(peerContext));
}
IEnumerable <INetworkMessageProcessor> processors = _serviceProvider.GetService <IEnumerable <INetworkMessageProcessor> >() !;
foreach (INetworkMessageProcessor processor in processors)
{
// skip processors that aren't enabled
if (!processor.Enabled)
{
continue;
}
peerContext.AttachNetworkMessageProcessor(processor);
await processor.AttachAsync(peerContext).ConfigureAwait(false);
}
peerContext.Features.Set(new PeerNetworkMessageProcessorContainer(_serviceProvider.GetRequiredService <ILogger <PeerNetworkMessageProcessorContainer> >(), processors));
}
public void Misbehave(IPeerContext peerContext, uint penality, string reason)
{
if (penality == 0)
{
return;
}
if (!_connectedPeers.TryGetValue(peerContext.PeerId, out PeerScore? score))
{
_logger.LogWarning("Cannot attribute bad behavior to the peer {PeerId} because the peer isn't connected.", peerContext.PeerId);
// did we have to add it to banned peers anyway?
return;
}
_logger.LogDebug("Peer {PeerId} misbehave: {MisbehaveReason}.", peerContext.PeerId, reason);
int currentResult = score.UpdateScore(-(int)penality);
if (currentResult < _connectivitySettings.BanScore)
{
//if threshold of bad behavior has been exceeded, this peer need to be banned
_logger.LogDebug("Peer {RemoteEndPoint} BAN threshold exceeded.", peerContext.RemoteEndPoint);
_peerAddressBook.Ban(peerContext, DateTimeOffset.UtcNow + TimeSpan.FromSeconds(_connectivitySettings.MisbehavingBanTime), "Peer Misbehaving");
}
}
public async ValueTask ProcessMessageAsync(INetworkMessage message, IPeerContext peerContext, CancellationToken cancellation)
{
await peerContext.Features.Get <PeerNetworkMessageProcessorContainer>().ProcessMessageAsync(message, cancellation).ConfigureAwait(false);
}
internal void SetPeerContext(IPeerContext peerContext)
{
this.peerContext = peerContext;
}
internal override void Completed(MediatorContext mediatorContext, IClientContext clientContext, IPeerContext peerContext, OperationCompletedEventArgs oce)
{
ClientConst.OperationResult operationResult = oce.Result;
if (operationResult == ClientConst.OperationResult.Successful)
{
Logger.GetLog().Info("接続を維持しています（接続数: " + peerContext.Connections + "）。");
mediatorContext.State = new ConnectedState();
}
else if (operationResult == ClientConst.OperationResult.Restartable)
{
Logger.GetLog().Info("IPアドレスが変化しているため、再接続します。");
peerContext.DisconnectAll();
Logger.GetLog().Info("ピア接続をすべて切断しました（接続数: " + peerContext.Connections + "）");
mediatorContext.State = new DisconnectedState();
bool result = mediatorContext.Connect();
if (!result)
{
mediatorContext.State = new ConnectedState();
}
}
else if (operationResult == ClientConst.OperationResult.Retryable)
{
// FIXME: 暫定。本当はすぐに再試行したい
Logger.GetLog().Info("接続維持に失敗しました。再試行可能なエラーです。");
mediatorContext.State = new ConnectedState();
}
else
{
throw new NotSupportedException();
}
}