/// <summary>
/// Find contact's closest nodes to id
/// </summary>
/// <param name="node">Node to query</param>
/// <param name="id">Id to compare</param>
/// <returns>Closest nodes to id</returns>
public IEnumerable <ContactNode> FindNode(ContactNode node, Id id)
{
Message.MnlMessage msg = new Message.MnlMessage.Builder()
.SetType(MessageType.Query)
.SetQueryType(QueryType.FindNode)
.SetOriginatorId(Id)
.Build();
msg.Payload.Add("target", id.Value);
Message.MnlMessage response = _server.SendMessageSync(node, msg, _validateMsgs, TimeoutInMSec).Response;
List <ContactNode> nodes = new List <ContactNode>();
if (response == null)
{
return(nodes);
}
UpdateLastSeen(node);
if (response.Payload.ContainsKey("nodes"))
{
byte[] nodeString = (byte[])response.Payload["nodes"];
int offset = 0;
while (offset < nodeString.Length)
{
nodes.Add(new ContactNode(nodeString, ref offset));
}
}
return(nodes);
}
public void SendBadToken(IPEndPoint toEndPoint)
{
Message.MnlMessage badTokenMsg = new Message.MnlMessage.Builder()
.SetType(MessageType.Error)
.SetErrorCode(ErrorType.ProtocolError)
.SetErrorMessage("Bad token")
.Build();
SendMessage(toEndPoint, badTokenMsg);
}
/// <summary>
/// Pings other node
/// </summary>
/// <param name="node">Node to ping</param>
/// <returns></returns>
public MnlMessage Ping(IPEndPoint nodeEndPoint)
{
Message.MnlMessage msg = new Message.MnlMessage.Builder()
.SetType(MessageType.Query)
.SetQueryType(QueryType.Ping)
.SetOriginatorId(Id)
.Build();
//do not validate id if we don't know nothing about node except it's address
return(_server.SendMessageSync(new ContactNode(Id, nodeEndPoint), msg, false, TimeoutInMSec).Response);
}
/// <summary>
/// Pings other node
/// </summary>
/// <param name="node">Node to ping</param>
/// <returns></returns>
public MnlMessage Ping(ContactNode node)
{
Message.MnlMessage msg = new Message.MnlMessage.Builder()
.SetType(MessageType.Query)
.SetQueryType(QueryType.Ping)
.SetOriginatorId(Id)
.Build();
UpdateLastSeen(node);
return(_server.SendMessageSync(node, msg, _validateMsgs, TimeoutInMSec).Response);
}
/// <summary>
/// Find contact's closest nodes to id
/// </summary>
/// <param name="node">Node to query</param>
/// <param name="id">Id to compare</param>
/// <returns>Closest nodes to id</returns>
public bool GetPeers(ContactNode node, Id infohash, out IEnumerable <ContactNode> nodes, out object token)
{
Message.MnlMessage msg = new Message.MnlMessage.Builder()
.SetType(MessageType.Query)
.SetQueryType(QueryType.GetPeers)
.SetOriginatorId(Id)
.SetInfohash(infohash)
.Build();
UpdateLastSeen(node);
Message.MnlMessage response = _server.SendMessageSync(node, msg, _validateMsgs, TimeoutInMSec).Response;
List <ContactNode> contacts = new List <ContactNode>();
nodes = contacts;
token = null;
if (response == null)
{
return(false);
}
if (response.Payload.ContainsKey("token"))
{
token = response.Payload["token"];
}
if (response.Payload.ContainsKey("values"))
{
List <object> valuesStrings = (List <object>)response.Payload["values"];
foreach (object peerInfo in valuesStrings)
{
contacts.Add(ContactNode.FromPeerInfo(peerInfo as byte[]));
}
return(true);
}
else if (response.Payload.ContainsKey("nodes"))
{
byte[] nodeString = (byte[])response.Payload["nodes"];
int offset = 0;
while (offset < nodeString.Length)
{
contacts.Add(new ContactNode(nodeString, ref offset));
}
return(false);
}
return(false);
}
/// <summary>
/// Find contact's closest nodes to id
/// </summary>
/// <param name="node">Node to query</param>
/// <param name="id">Id to compare</param>
/// <returns></returns>
public MnlMessage AnnouncePeer(ContactNode node, Id infohash, int port, object token, int?impliedPort)
{
Message.MnlMessage msg = new Message.MnlMessage.Builder()
.SetType(MessageType.Query)
.SetQueryType(QueryType.AnnouncePeer)
.SetOriginatorId(Id)
.SetInfohash(infohash)
.Build();
msg.Payload.Add("port", port);
msg.Payload.Add("implied_port", impliedPort ?? 0);
msg.Payload.Add("token", token ?? new byte[0]);
UpdateLastSeen(node);
return(_server.SendMessageSync(node, msg, _validateMsgs, TimeoutInMSec).Response);
}
private void ListenIncoming(Node ownerNode)
{
while (!_stopped)
{
try {
IPEndPoint incomingIpEndPoint = new IPEndPoint(IPAddress.Any, EndPoint.Port);
byte[] rawMsg = _udpClient.Receive(ref incomingIpEndPoint);
if (!IsLegitMnlDhtMessage(rawMsg))
{
continue;
}
Message.MnlMessage incomingMsg = null;
try {
incomingMsg = new Message.MnlMessage.Builder(rawMsg).Build();
} catch (Bittorrent.InvalidFieldException ife) {
MnlMessage errMessage = new MnlMessage.Builder()
.SetTranId(GenerateTranId())
.SetType(MessageType.Error)
.SetErrorCode(ErrorType.ProtocolError)
.SetErrorMessage(ife.Message)
.Build();
Debug.WriteLine($"Sending incorrect field message {ife.Message}");
SendMessage(incomingIpEndPoint, errMessage);
continue;
} catch (MalformedPacketException mpe) {
MnlMessage errMessage = new MnlMessage.Builder()
.SetTranId(GenerateTranId())
.SetType(MessageType.Error)
.SetErrorCode(ErrorType.ProtocolError)
.SetErrorMessage(mpe.Message)
.Build();
Debug.WriteLine($"Sending malformed packet message {mpe.Message}");
SendMessage(incomingIpEndPoint, errMessage);
continue;
}
ulong msgIdx = GetMessageId(incomingIpEndPoint.Address, BitConverter.ToUInt16(Encoding.ASCII.GetBytes(incomingMsg.TranId.PadLeft(2, '\0')), 0));
if (_messages.ContainsKey(msgIdx))
{
PendingMnlMessage rqMsg;
if (_messages.TryRemove(msgIdx, out rqMsg))
{
if (incomingMsg.Type == MessageType.Error)
{
Debug.WriteLine($"Recieved error {incomingMsg.ErrorMessage}");
switch (incomingMsg.ErrorCode)
{
case ErrorType.ProtocolError:
case ErrorType.MethodUnknown:
Debug.WriteLine($"!!!Error {incomingMsg.ErrorMessage}");
break;
default:
continue;
}
}
if (rqMsg.ValidateId)
{
if (rqMsg.RecipientId != incomingMsg.OriginatorId)
{
Debug.WriteLine($"Node {incomingIpEndPoint} id mismatch!");
OnMaliciousMessage?.Invoke(incomingIpEndPoint, rqMsg.RecipientId, rqMsg.SentMessage);
continue;
}
}
rqMsg.SentMessage.SetResponse(incomingMsg);
}
}
else
{
if (incomingMsg.Type == MessageType.Query)
{
ownerNode.ProcessQuery(incomingMsg, incomingIpEndPoint);
}
}
} catch (SocketException se) {
if (se.SocketErrorCode != SocketError.Interrupted)
{
throw;
}
}
}
}