private void SendConnectionRequest(TrackerGetUdpEntry entry)
{
SocketBuffer outgoing = new SocketBuffer(16);
Array.Copy(TrackerGetUdpProtocol.Id, 0, outgoing.Data, 0, 8);
Array.Copy(TrackerGetUdpProtocol.Connect, 0, outgoing.Data, 8, 4);
Array.Copy(entry.Transaction, 0, outgoing.Data, 12, 4);
entry.Status = TrackerGetUdpStatus.Connecting;
socket.Send(entry.Endpoint, outgoing, OnSent(entry));
}
public TrackerGetUdpEntry Add(byte[] transaction)
{
TrackerGetUdpEntry entry = new TrackerGetUdpEntry
{
Status = TrackerGetUdpStatus.Pending,
Transaction = transaction,
};
items.Add(transaction, entry);
return(entry);
}
private void HandleErrorResponse(IPEndPoint endpoint, TrackerGetUdpEntry entry, byte[] data)
{
if (data.Length < 8)
{
context.CallPacketIgnored(endpoint, data.Length);
return;
}
byte[] message = Bytes.Copy(data, 8);
string reason = Encoding.ASCII.GetString(message);
context.CallFailed(entry.Address, entry.Request.Hash, reason);
}
public void Register(TrackerGetUdpRegistrant registrant)
{
byte[] transaction = Bytes.Random(4);
TrackerGetUdpEntry entry = collection.Add(transaction);
entry.Host = registrant.Host;
entry.Port = registrant.Port;
entry.Request = registrant.Request;
entry.Callback = registrant.Callback;
entry.Address = new Uri($"udp://{entry.Host}:{entry.Port}");
entry.Deadline = DateTime.Now + TimeSpan.FromSeconds(context.Configuration.Timeout);
}
private UdpSocketSendCallback OnSent(TrackerGetUdpEntry entry)
{
return(sent =>
{
if (sent.Status == SocketStatus.OK)
{
int size = sent.Count;
IPEndPoint endpoint = sent.Endpoint;
context.Queue.Add(() =>
{
context.CallPacketSent(entry.Address, entry.Request.Hash, endpoint, size);
});
}
});
}
private void ResolveHost(TrackerGetUdpEntry entry)
{
try
{
entry.Status = TrackerGetUdpStatus.Resolving;
IPHostEntry found = Dns.GetHostEntry(entry.Host);
IPAddress address = found.AddressList.FirstOrDefault();
entry.Endpoint = new IPEndPoint(address, entry.Port);
entry.Status = TrackerGetUdpStatus.Resolved;
}
catch (Exception ex)
{
context.CallFailed(entry.Address, entry.Request.Hash, ex.Message);
}
}
private void HandleAnnounceResponse(IPEndPoint endpoint, TrackerGetUdpEntry entry, byte[] data)
{
if (data.Length < 20)
{
context.CallPacketIgnored(endpoint, data.Length);
return;
}
if (Bytes.Equals(TrackerGetUdpProtocol.Announce, data, 0, 4) == false)
{
context.CallPacketIgnored(endpoint, data.Length);
return;
}
List <NetworkAddress> peers = new List <NetworkAddress>();
int intervalInSeconds = Bytes.ReadInt32(data, 8);
TimeSpan interval = TimeSpan.FromSeconds(intervalInSeconds);
int leechers = Bytes.ReadInt32(data, 12);
int seeders = Bytes.ReadInt32(data, 16);
for (int i = 20; i + 6 <= data.Length; i += 6)
{
int port = Bytes.ReadUInt16(data, i + 4);
StringBuilder address = new StringBuilder();
address.Append(data[i].ToString());
address.Append('.');
address.Append(data[i + 1].ToString());
address.Append('.');
address.Append(data[i + 2].ToString());
address.Append('.');
address.Append(data[i + 3].ToString());
if (port > 0)
{
peers.Add(new NetworkAddress(address.ToString(), port));
}
}
collection.Remove(entry.Transaction);
entry.Callback.Invoke(interval);
context.CallAnnounced(entry.Address, entry.Request.Hash, interval, seeders, leechers, peers.ToArray());
}
private void HandleConnectionResponse(IPEndPoint endpoint, TrackerGetUdpEntry entry, byte[] data)
{
if (data.Length < 16)
{
context.CallPacketIgnored(endpoint, data.Length);
return;
}
if (Bytes.Equals(TrackerGetUdpProtocol.Connect, data, 0, 4) == false)
{
context.CallPacketIgnored(endpoint, data.Length);
return;
}
entry.Connection = Bytes.Copy(data, 8, 8);
entry.Status = TrackerGetUdpStatus.Connected;
context.CallConnected(entry.Address, entry.Request.Hash, entry.Transaction, entry.Connection);
}
private void SendAnnounceRequest(TrackerGetUdpEntry entry)
{
SocketBuffer outgoing = new SocketBuffer(98);
PeerHash peer = context.Configuration.Peer;
outgoing[67] = 0x01;
outgoing[83] = 0x02;
outgoing[95] = 0xff;
outgoing[96] = 0x1f;
outgoing[97] = 0x90;
Array.Copy(entry.Connection, 0, outgoing.Data, 0, 8);
Array.Copy(TrackerGetUdpProtocol.Announce, 0, outgoing.Data, 8, 4);
Array.Copy(entry.Transaction, 0, outgoing.Data, 12, 4);
Array.Copy(entry.Request.Hash.ToBytes(), 0, outgoing.Data, 16, 20);
Array.Copy(peer.ToBytes(), 0, outgoing.Data, 36, 20);
entry.Status = TrackerGetUdpStatus.Announcing;
socket.Send(entry.Endpoint, outgoing, OnSent(entry));
}
private Action OnReceived(IPEndPoint endpoint, byte[] data)
{
return(() =>
{
context.CallPacketReceived(endpoint, data.Length);
if (data.Length < 8)
{
context.CallPacketIgnored(endpoint, data.Length);
return;
}
byte[] transaction = Bytes.Copy(data, 4, 4);
TrackerGetUdpEntry entry = collection.Find(transaction);
if (entry != null && Bytes.Equals(TrackerGetUdpProtocol.Error, data, 0, 4))
{
HandleErrorResponse(endpoint, entry, data);
return;
}
switch (entry?.Status)
{
case TrackerGetUdpStatus.Connecting:
HandleConnectionResponse(endpoint, entry, data);
break;
case TrackerGetUdpStatus.Announcing:
HandleAnnounceResponse(endpoint, entry, data);
break;
default:
context.CallPacketIgnored(endpoint, data.Length);
break;
}
});
}
private void HandleDeadline(TrackerGetUdpEntry entry)
{
collection.Remove(entry.Transaction);
context.CallTimeout(entry.Address, entry.Request.Hash);
}
