public override int Flush() { var numChunks = ResendQueueConstruct.NumChunks; if (numChunks == 0 && ResendQueueConstruct.Flags == PacketFlags.NONE) { return(0); } ResendQueueConstruct.Ack = Ack; if (UseToken) { ResendQueueConstruct.Flags |= PacketFlags.TOKEN; ResendQueueConstruct.Token = Token; } NetworkCore.SendPacket(UdpClient, EndPoint, ResendQueueConstruct); LastSendTime = Time.Get(); ResetQueueConstruct(); return(numChunks); }
public override bool Receive(out NetworkChunk packet) { while (true) { if (ChunkReceiver.FetchChunk(out packet)) { return(true); } if (UdpClient.Available <= 0) { return(false); } var remote = (IPEndPoint)null; byte[] data; try { data = UdpClient.Receive(ref remote); } catch { continue; } if (data.Length <= 0) { continue; } if (!NetworkCore.UnpackPacket(data, data.Length, ChunkReceiver.ChunkConstruct)) { continue; } var useToken = false; var token = (uint)0; if (ChunkReceiver.ChunkConstruct.Flags.HasFlag(PacketFlags.TOKEN)) { useToken = true; token = ChunkReceiver.ChunkConstruct.Token; } else if (ChunkReceiver.ChunkConstruct.Flags.HasFlag(PacketFlags.CONTROL) && ChunkReceiver.ChunkConstruct.Data[0] == (int)ConnectionMessages.CONNECT && ChunkReceiver.ChunkConstruct.DataSize >= 1 + 512) { useToken = true; token = ChunkReceiver.ChunkConstruct.Data.ToUInt32(5); } if (NetworkBan.IsBanned(remote, out var reason)) { NetworkCore.SendControlMsg(UdpClient, remote, 0, useToken, token, ConnectionMessages.CLOSE, reason); continue; } if (ChunkReceiver.ChunkConstruct.Flags.HasFlag(PacketFlags.CONNLESS)) { packet = new NetworkChunk { ClientId = -1, Flags = SendFlags.CONNLESS, EndPoint = remote, DataSize = ChunkReceiver.ChunkConstruct.DataSize, Data = ChunkReceiver.ChunkConstruct.Data }; return(true); } var clientId = FindSlot(remote, true); if (ChunkReceiver.ChunkConstruct.Flags.HasFlag(PacketFlags.CONTROL) && ChunkReceiver.ChunkConstruct.Data[0] == (int)ConnectionMessages.CONNECT) { if (clientId != -1) { continue; } if (ChunkReceiver.ChunkConstruct.DataSize >= 1 + 512) { var connectAccept = new byte[4]; GetToken(remote).ToByteArray(connectAccept, 0); NetworkCore.SendControlMsg(UdpClient, remote, 0, true, token, ConnectionMessages.CONNECTACCEPT, connectAccept); Debug.Log("netserver", "got connect, sending connect+accept challenge"); } else if (Config["SvAllowOldClients"].AsBoolean() && string.IsNullOrWhiteSpace(Config["Password"].AsString())) { if (LegacyRateLimit()) { Debug.Log("netserver", "dropping legacy connect due to ratelimit"); continue; } var packets = new NetworkChunkConstruct[] { new NetworkChunkConstruct(), new NetworkChunkConstruct(), }; var legacyToken = GetLegacyToken(remote); ConstructLegacyHandshake(packets[0], packets[1], legacyToken); for (var i = 0; i < 2; i++) { NetworkCore.SendPacket(UdpClient, remote, packets[i]); } Debug.Log("netserver", "got legacy connect, sending legacy challenge"); } else { Debug.Log("netserver", $"dropping short connect packet, size={ChunkReceiver.ChunkConstruct.DataSize}"); } } else { if (clientId == -1) { if (!useToken || !IsCorrectToken(remote, token)) { if (!useToken && Config["SvAllowOldClients"].AsBoolean()) { ChunkReceiver.Start(remote, null, -1); var chunk = new NetworkChunk(); var correct = false; while (ChunkReceiver.FetchChunk(out chunk)) { if (DecodeLegacyHandShake(chunk.Data, chunk.DataSize, out var legacyToken)) { if (IsCorrectLegacyToken(remote, legacyToken)) { correct = true; break; } } } ChunkReceiver.Clear(); if (!correct) { continue; } } else { Debug.Log("netserver", !useToken ? "dropping packet with missing token" : $"dropping packet with invalid token, token={token}"); continue; } } var sameIps = 0; for (var i = 0; i < Connections.Length; i++) { if (Connections[i].State == ConnectionState.OFFLINE) { if (clientId < 0) { clientId = i; } continue; } if (!NetworkCore.CompareEndPoints(Connections[i].EndPoint, remote, false)) { continue; } sameIps++; if (sameIps >= ServerConfig.MaxClientsPerIp) { NetworkCore.SendControlMsg(UdpClient, remote, 0, useToken, token, ConnectionMessages.CLOSE, $"Only {ServerConfig.MaxClientsPerIp} players with the same IP are allowed"); return(false); } } if (clientId < 0) { for (var i = 0; i < Connections.Length; i++) { if (Connections[i].State == ConnectionState.OFFLINE) { clientId = i; break; } } } if (clientId < 0) { NetworkCore.SendControlMsg(UdpClient, remote, 0, useToken, token, ConnectionMessages.CLOSE, "This server is full"); return(false); } if (useToken) { Connections[clientId].Accept(remote, token); } else { Connections[clientId].AcceptLegacy(remote); } NewClientCallback?.Invoke(clientId, !useToken); if (!useToken) { continue; } Connections[clientId].Feed(ChunkReceiver.ChunkConstruct, remote); } if (Connections[clientId].Feed(ChunkReceiver.ChunkConstruct, remote)) { if (ChunkReceiver.ChunkConstruct.DataSize != 0) { ChunkReceiver.Start(remote, Connections[clientId], clientId); } } } } }