/// <summary>
/// Helper method that catches new messages (and handles connection exceptions).
/// When an exception occurs, we will disconnect with the peer.
/// </summary>
/// <param name="node">The node to listen to</param>
/// <param name="timeout">The message timeout to maintain. Disconnect when timeout has been exceeded.</param>
/// <returns>The message that we received from the node</returns>
public async Task <Message> ListenForNewMessage(NetworkNode node, TimeSpan timeout)
{
try
{
var msg = await node.ReceiveMessageAsync(timeout);
/*
* var delaySec = 0;
* Random rnd = new Random();
* int delayChance = rnd.Next(1, 100);
* if (delayChance > 55 && delayChance < 86)
* {
* delaySec = rnd.Next(1, 3);
* }
* else if (delayChance > 85 && delayChance < 96)
* {
* delaySec = rnd.Next(3, 6);
* }
* else if (delayChance > 95 && delayChance < 101)
* {
* delaySec = rnd.Next(7, 13);
* }
*
* await Task.Delay(delaySec * 1000);
*/
return(msg);
}
catch (Exception)
{
await node?.Disconnect();
}
return(null);
}
public override async Task HandleMessage(NetworkNode node, Message msg)
{
if (node.HandshakeIsCompleted)
{
return;
}
var blockchain = _blockchainRepo.GetChainByNetId(_netId);
try
{
if (node.ConnectionType == ConnectionType.Inbound)
{
await HandleInboundHandshakeMessage(node, msg, blockchain);
}
else
{
await HandleOutboundHandshakeMessage(node, msg, blockchain);
}
}
catch (Exception)
{
node?.Disconnect();
}
}
public void Disconnect()
{
OnDisconnect?.Invoke();
NetworkNode.Disconnect(NetworkAddress);
}
private static void Main(String[] args)
{
string servers;
if (args.Length == 3)
{
_port = int.Parse(args[0]);
servers = args[1];
_mesh = bool.Parse(args[2]);
}
else
{
Console.Write("Input a port to run on: ");
_port = int.Parse(Console.ReadLine());
Console.Write("Input a comma separated list of servers to connect to: ");
servers = Console.ReadLine();
Console.Write("Is this a mesh network or chord network? (\"mesh\" for mesh and \"chord\" for chord): ");
string networkType = Console.ReadLine();
if (networkType == "mesh")
{
_mesh = true;
}
else if (networkType == "chord")
{
_mesh = false;
}
else
{
Console.WriteLine("Unknown network type.");
return;
}
}
if (_mesh)
{
_node = new MeshNetworkNode("MeshNetworkTester" + _port + ".log", LogLevels.Warning);
}
else
{
_node = new ChordNetworkNode("MeshNetworkTester" + _port + ".log", LogLevels.Warning);
}
_node.ReceivedMessage += node_ReceivedMessage;
_node.ConnectToNetwork(_port,
servers.Split(new char[] { ',' }, StringSplitOptions.RemoveEmptyEntries)
.Select(e => new NodeProperties(e))
.ToList());
var thisMachine = new NodeProperties("localhost", _port);
Console.WriteLine("Please enter a command, or type \"help\" for help.");
bool running = true;
while (running)
{
Console.Write(" > ");
string command = Console.ReadLine();
switch (command)
{
case "custom":
Console.WriteLine("Node to send data to: ");
string node = Console.ReadLine();
Console.WriteLine("Data to send: ");
string data = Console.ReadLine();
_node.SendMessage(new NodeProperties(node), data);
break;
case "exit":
Console.WriteLine("Shutting down node...");
running = false;
_node.Disconnect();
break;
case "help":
Console.WriteLine("exit: Exits the program\nstatus: Displays the status of the program\nread: Reads a value from the database\nwrite: Writes a value to the database\ncustom: Sends a custom message (warning: this will also output the message on the receiver's side immediately upon receiving it)");
break;
case "read":
Console.Write("What is the key (integer): ");
int key = int.Parse(Console.ReadLine());
string value = null;
// If the value is local, read it, otherwise go get it.
if (database.ContainsKey(key))
{
value = database[key];
}
else
{
if (_node is MeshNetworkNode)
{
// Search every node for the value.
List <MessageResponseResult> results = new List <MessageResponseResult>();
foreach (var neighbor in _node.GetNeighbors())
{
results.Add(_node.SendMessageResponse(neighbor, "read" + key));
}
foreach (var result in results)
{
if (result.SendResult == SendResults.Success &&
result.ResponseResult == ResponseResults.Success)
{
if (result.ResponseMessage.Data.StartsWith("y"))
{
value = result.ResponseMessage.Data.Substring(1);
break;
}
}
}
}
else
{
// Search for the node that contains the value.
var result = ((ChordNetworkNode)_node).SendChordMessageResponse(key, "read" + key);
if (result.SendResult == SendResults.Success &&
result.ResponseResult == ResponseResults.Success)
{
if (result.ResponseMessage.Data.StartsWith("y"))
{
value = result.ResponseMessage.Data.Substring(1);
}
}
}
}
if (value == null)
{
Console.WriteLine("Could not find a value associated with the key " + key + ".");
}
else
{
Console.WriteLine("Key: " + key + " Value: " + value);
}
break;
case "status":
Console.WriteLine("Currently running on " + thisMachine.IpAddress + ":" + thisMachine.Port);
Console.WriteLine();
if (_node is MeshNetworkNode)
{
var neighbors = _node.GetNeighbors();
Console.WriteLine("Connected Nodes: ");
foreach (var neighbor in neighbors)
{
Console.WriteLine(neighbor.IpAddress + ":" + neighbor.Port);
}
Console.WriteLine("Currently connected to " + neighbors.Count + " nodes.");
}
else
{
var chordNode = (ChordNetworkNode)_node;
Console.WriteLine("id: " + chordNode.Id + " Predecessor: " + chordNode.Predecessor +
" Successor: " +
(chordNode.Successor == null ? "self" : chordNode.Successor.ToString()));
Console.WriteLine("Fingers:");
foreach (var finger in chordNode.GetFingers())
{
Console.WriteLine(finger.IpAddress + ":" + finger.Port);
}
}
break;
case "write":
Console.Write("What is the key (integer): ");
key = int.Parse(Console.ReadLine());
Console.Write("What is the value (string): ");
value = Console.ReadLine();
if (_node is MeshNetworkNode)
{
// If this is a mesh network, write the value locally.
SetValue(key, value);
}
else
{
// Find the node that should contain the value and write it there.
var dataNode = ((ChordNetworkNode)_node).GetNodeContainingId(key);
if (dataNode == null || dataNode.Equals(thisMachine))
{
SetValue(key, value);
}
else
{
((ChordNetworkNode)_node).SendChordMessage(key, "write" + key + " " + value);
}
}
break;
default:
Console.WriteLine("Unknown command.");
break;
}
}
}
// todo Chain of Responsibility pattern, make XXMessageHandler class for each command type
// and refactor abstractmessagehandler to a regular MessageHandlerHelper
public override async Task HandleMessage(NetworkNode node, Message msg)
{
try
{
if (msg.Command == NetworkCommand.CloseConn.ToString())
{
await node.Disconnect();
}
else if (msg.Command == NetworkCommand.GetAddr.ToString())
{
// Send our known peers
var addresses = new AddrPayload(_nodePool.GetAllRemoteListenEndpoints());
await SendMessageToNode(node, NetworkCommand.Addr, addresses);
}
else if (msg.Command == NetworkCommand.Addr.ToString())
{
// Connect to all neighbors that the other node knows
var payload = (AddrPayload)msg.Payload;
foreach (IPEndPoint endpoint in payload.Endpoints)
{
await _networkManager.ConnectToPeer(endpoint);
}
}
else if (msg.Command == NetworkCommand.GetHeaders.ToString())
{
// Send our headers
var payload = (GetHeadersPayload)msg.Payload;
try
{
var headers = GetBlocksFromHash(payload.HighestHeightHash, payload.StoppingHash, false).Select(b => b.Header);
var headersPayload = new HeadersPayload(headers);
await SendMessageToNode(node, NetworkCommand.Headers, headersPayload);
}
catch (KeyNotFoundException)
{
// Send empty payload
await SendMessageToNode(node, NetworkCommand.NotFound, null);
}
}
else if (msg.Command == NetworkCommand.GetBlocks.ToString())
{
var payload = (GetBlocksPayload)msg.Payload;
var blocksPayload = new StateBlocksPayload();
if (payload.Headers.Count() > 0)
{
blocksPayload = new StateBlocksPayload(GetBlocksFromHash(payload.Headers.First(), payload.Headers.Last(), true));
}
await SendMessageToNode(node, NetworkCommand.Blocks, blocksPayload);
}
else if (msg.Command == NetworkCommand.Headers.ToString() && node.IsSyncingWithNode)
{
node.SetSyncStatus(SyncStatus.InProgress);
var headersPayload = (HeadersPayload)msg.Payload;
if (headersPayload.Headers.Count() == 0)
{
_logger.LogInformation("Successfully synced with remote node.");
node.SetSyncStatus(SyncStatus.Succeeded);
return;
}
// Request these blocks
var getBlocksPayload = new GetBlocksPayload(headersPayload.Headers.Select(h => h.Hash));
await SendMessageToNode(node, NetworkCommand.GetBlocks, getBlocksPayload);
}
else if (msg.Command == NetworkCommand.NotFound.ToString() && node.IsSyncingWithNode)
{
node.SetSyncStatus(SyncStatus.Failed); // Restart the syncing process with another node.
}
else if (msg.Command == NetworkCommand.Blocks.ToString() && node.IsSyncingWithNode)
{
var blocksPayload = (StateBlocksPayload)msg.Payload;
// Todo rewrite this code to support multithreaded 'Blocks' messages. Combine all gathered blocks
// until the process has completed and all blocks are downloaded. Then, grab a block that points to the
// end of our chain and add it to our chain. Repeat that process until all blocks have been added.
var blocksProcessed = 0;
lock (_blockchain)
{
while (blocksPayload.Blocks.Where(b => b.Header.PreviousHash == _blockchain.Blocks.Last().Header.Hash).Any())
{
var blockToProcess = blocksPayload.Blocks.Where(b => b.Header.PreviousHash == _blockchain.Blocks.Last().Header.Hash).First();
if (_blockchain.CurrentHeight % 5 == 0 && _blockchain.CurrentHeight > 0)
{
_difficulty = _difficultyCalculator.CalculateCurrentDifficulty(_blockchain); // todo use CalculateCurrentDifficulty when testing is done
}
if (_difficulty < 1)
{
_difficulty = 1;
}
var currentTarget = BlockchainConstants.MaximumTarget / _difficulty; // todo refactor these 3 lines. They are copy-pasted from the miner.
_blockValidator.ValidateBlock(blockToProcess, currentTarget, _blockchain, false, true); // Rethrow when we have a Block- / TransactionRejectedException. We don't want to keep a connection with bad nodes.
blocksProcessed++;
}
}
_logger.LogDebug("Downloaded and added {0} new blocks from remote node", blocksProcessed);
_logger.LogDebug("Current height: {0}", _blockchain.CurrentHeight);
if (blocksProcessed != blocksPayload.Blocks.Count())
{
_logger.LogError("Added {0} new blocks from remote node, but expected {1}. Sync failed.", blocksProcessed, blocksPayload.Blocks.Count());
node.SetSyncStatus(SyncStatus.Failed);
return;
}
_blockchainRepo.Update(_blockchain);
// Block batch processed. Keep on ask for more headers.
var getHeadersPayload = new GetHeadersPayload(_blockchain.Blocks.Last().Header.Hash);
await SendMessageToNode(node, NetworkCommand.GetHeaders, getHeadersPayload);
}
else if (msg.Command == NetworkCommand.GetTxPool.ToString())
{
var txPoolPayload = new StateTransactionsPayload(_txPool.GetAllTransactions());
await SendMessageToNode(node, NetworkCommand.TxPool, txPoolPayload);
}
else if (msg.Command == NetworkCommand.TxPool.ToString())
{
var txPoolPayload = (StateTransactionsPayload)msg.Payload;
foreach (var tx in txPoolPayload.Transactions)
{
_txPool.AddTransaction(tx);
}
}
else if (msg.Command == NetworkCommand.NewTransaction.ToString())
{
var txPayload = (SingleStateTransactionPayload)msg.Payload;
if (_networkManager.IsSyncing)
{
return;
}
var validationResult = EventPublisher.GetInstance().PublishUnvalidatedTransactionReceived(node, new TransactionReceivedEventArgs(txPayload.Transaction));
if (validationResult == false)
{
//await node.Disconnect(); // Dishonest node, buuh!
}
}
else if (msg.Command == NetworkCommand.NewBlock.ToString())
{
var blockPayload = (SingleStateBlockPayload)msg.Payload;
if (_networkManager.IsSyncing)
{
return;
}
var validationResult = EventPublisher.GetInstance().PublishUnvalidatedBlockCreated(node, new BlockCreatedEventArgs(blockPayload.Block));
if (validationResult == false)
{
//await node.Disconnect(); // Dishonest node, buuh!
}
}
}
catch (Exception ex)
{
_logger.LogError("An {0} occurred during the process of handling a {1} message: {2}. Node will be disconnected.", ex.GetType().Name, msg.Command.ToString(), ex.Message);
node?.Disconnect();
}
}