IW4M-Admin/Application/RCon/RConConnection.cs

451 lines
19 KiB
C#

using SharedLibraryCore;
using SharedLibraryCore.Exceptions;
using SharedLibraryCore.Interfaces;
using SharedLibraryCore.RCon;
using System;
using System.Collections.Concurrent;
using System.Collections.Generic;
using System.Linq;
using System.Net;
using System.Net.Sockets;
using System.Text;
using System.Text.RegularExpressions;
using System.Threading.Tasks;
using Microsoft.Extensions.Logging;
using Serilog.Context;
using ILogger = Microsoft.Extensions.Logging.ILogger;
namespace IW4MAdmin.Application.RCon
{
/// <summary>
/// implementation of IRConConnection
/// </summary>
public class RConConnection : IRConConnection
{
static readonly ConcurrentDictionary<EndPoint, ConnectionState> ActiveQueries = new ConcurrentDictionary<EndPoint, ConnectionState>();
public IPEndPoint Endpoint { get; private set; }
public string RConPassword { get; private set; }
private IRConParser parser;
private IRConParserConfiguration config;
private readonly ILogger _log;
private readonly Encoding _gameEncoding;
public RConConnection(string ipAddress, int port, string password, ILogger<RConConnection> log, Encoding gameEncoding)
{
Endpoint = new IPEndPoint(IPAddress.Parse(ipAddress), port);
_gameEncoding = gameEncoding;
RConPassword = password;
_log = log;
}
public void SetConfiguration(IRConParser parser)
{
this.parser = parser;
config = parser.Configuration;
}
public async Task<string[]> SendQueryAsync(StaticHelpers.QueryType type, string parameters = "")
{
if (!ActiveQueries.ContainsKey(this.Endpoint))
{
ActiveQueries.TryAdd(this.Endpoint, new ConnectionState());
}
var connectionState = ActiveQueries[this.Endpoint];
_log.LogDebug("Waiting for semaphore to be released [{endpoint}]", Endpoint);
// enter the semaphore so only one query is sent at a time per server.
await connectionState.OnComplete.WaitAsync();
var timeSinceLastQuery = (DateTime.Now - connectionState.LastQuery).TotalMilliseconds;
if (timeSinceLastQuery < StaticHelpers.FloodProtectionInterval)
{
await Task.Delay(StaticHelpers.FloodProtectionInterval - (int)timeSinceLastQuery);
}
connectionState.LastQuery = DateTime.Now;
_log.LogDebug("Semaphore has been released [{endpoint}]", Endpoint);
_log.LogDebug("Query {@queryInfo}", new { endpoint=Endpoint.ToString(), type, parameters });
byte[] payload = null;
bool waitForResponse = config.WaitForResponse;
string convertEncoding(string text)
{
byte[] convertedBytes = Utilities.EncodingType.GetBytes(text);
return _gameEncoding.GetString(convertedBytes);
}
try
{
string convertedRConPassword = convertEncoding(RConPassword);
string convertedParameters = convertEncoding(parameters);
switch (type)
{
case StaticHelpers.QueryType.GET_DVAR:
waitForResponse |= true;
payload = string.Format(config.CommandPrefixes.RConGetDvar, convertedRConPassword, convertedParameters + '\0').Select(Convert.ToByte).ToArray();
break;
case StaticHelpers.QueryType.SET_DVAR:
payload = string.Format(config.CommandPrefixes.RConSetDvar, convertedRConPassword, convertedParameters + '\0').Select(Convert.ToByte).ToArray();
break;
case StaticHelpers.QueryType.COMMAND:
payload = string.Format(config.CommandPrefixes.RConCommand, convertedRConPassword, convertedParameters + '\0').Select(Convert.ToByte).ToArray();
break;
case StaticHelpers.QueryType.GET_STATUS:
waitForResponse |= true;
payload = (config.CommandPrefixes.RConGetStatus + '\0').Select(Convert.ToByte).ToArray();
break;
case StaticHelpers.QueryType.GET_INFO:
waitForResponse |= true;
payload = (config.CommandPrefixes.RConGetInfo + '\0').Select(Convert.ToByte).ToArray();
break;
case StaticHelpers.QueryType.COMMAND_STATUS:
waitForResponse |= true;
payload = string.Format(config.CommandPrefixes.RConCommand, convertedRConPassword, "status\0").Select(Convert.ToByte).ToArray();
break;
}
}
// this happens when someone tries to send something that can't be converted into a 7 bit character set
// e.g: emoji -> windows-1252
catch (OverflowException ex)
{
connectionState.OnComplete.Release(1);
using (LogContext.PushProperty("Server", Endpoint.ToString()))
{
_log.LogError(ex, "Could not convert RCon data payload to desired encoding {encoding} {params}",
_gameEncoding.EncodingName, parameters);
}
throw new RConException($"Invalid character encountered when converting encodings");
}
byte[][] response = null;
retrySend:
if (connectionState.ConnectionAttempts > 1)
{
using (LogContext.PushProperty("Server", Endpoint.ToString()))
{
_log.LogInformation(
"Retrying RCon message ({connectionAttempts}/{allowedConnectionFailures} attempts) with parameters {payload}",
connectionState.ConnectionAttempts,
StaticHelpers.AllowedConnectionFails, parameters);
}
}
using (var socket = new Socket(AddressFamily.InterNetwork, SocketType.Dgram, ProtocolType.Udp)
{
DontFragment = true,
Ttl = 100,
ExclusiveAddressUse = true,
})
{
connectionState.SendEventArgs.UserToken = socket;
connectionState.OnSentData.Reset();
connectionState.OnReceivedData.Reset();
connectionState.ConnectionAttempts++;
connectionState.BytesReadPerSegment.Clear();
bool exceptionCaught = false;
_log.LogDebug("Sending {payloadLength} bytes to [{endpoint}] ({connectionAttempts}/{allowedConnectionFailures})",
payload.Length, Endpoint, connectionState.ConnectionAttempts, StaticHelpers.AllowedConnectionFails);
try
{
response = await SendPayloadAsync(payload, waitForResponse, parser.OverrideTimeoutForCommand(parameters));
if ((response.Length == 0 || response[0].Length == 0) && waitForResponse)
{
throw new RConException("Expected response but got 0 bytes back");
}
connectionState.ConnectionAttempts = 0;
}
catch
{
// we want to retry with a delay
if (connectionState.ConnectionAttempts < StaticHelpers.AllowedConnectionFails)
{
exceptionCaught = true;
await Task.Delay(StaticHelpers.SocketTimeout(connectionState.ConnectionAttempts));
goto retrySend;
}
using (LogContext.PushProperty("Server", Endpoint.ToString()))
{
_log.LogWarning(
"Made {connectionAttempts} attempts to send RCon data to server, but received no response",
connectionState.ConnectionAttempts);
}
connectionState.ConnectionAttempts = 0;
throw new NetworkException("Reached maximum retry attempts to send RCon data to server");
}
finally
{
// we don't want to release if we're going to retry the query
if (connectionState.OnComplete.CurrentCount == 0 && !exceptionCaught)
{
connectionState.OnComplete.Release(1);
}
}
}
if (response.Length == 0)
{
_log.LogDebug("Received empty response for RCon request {@query}", new { endpoint=Endpoint.ToString(), type, parameters });
return new string[0];
}
string responseString = type == StaticHelpers.QueryType.COMMAND_STATUS ?
ReassembleSegmentedStatus(response) : RecombineMessages(response);
// note: not all games respond if the pasword is wrong or not set
if (responseString.Contains("Invalid password") || responseString.Contains("rconpassword"))
{
throw new RConException(Utilities.CurrentLocalization.LocalizationIndex["SERVER_ERROR_RCON_INVALID"]);
}
if (responseString.Contains("rcon_password"))
{
throw new RConException(Utilities.CurrentLocalization.LocalizationIndex["SERVER_ERROR_RCON_NOTSET"]);
}
if (responseString.Contains(config.ServerNotRunningResponse))
{
throw new ServerException(Utilities.CurrentLocalization.LocalizationIndex["SERVER_ERROR_NOT_RUNNING"].FormatExt(Endpoint.ToString()));
}
string responseHeaderMatch = Regex.Match(responseString, config.CommandPrefixes.RConResponse).Value;
string[] headerSplit = responseString.Split(type == StaticHelpers.QueryType.GET_INFO ? config.CommandPrefixes.RconGetInfoResponseHeader : responseHeaderMatch);
if (headerSplit.Length != 2)
{
using (LogContext.PushProperty("Server", Endpoint.ToString()))
{
_log.LogWarning("Invalid response header from server. Expected {expected}, but got {response}",
config.CommandPrefixes.RConResponse, headerSplit.FirstOrDefault());
}
throw new RConException("Unexpected response header from server");
}
string[] splitResponse = headerSplit.Last().Split(new char[] { '\n' }, StringSplitOptions.RemoveEmptyEntries);
return splitResponse;
}
/// <summary>
/// reassembles broken status segments into the 'correct' ordering
/// <remarks>this is primarily for T7, and is really only reliable for 2 segments</remarks>
/// </summary>
/// <param name="segments">array of segmented byte arrays</param>
/// <returns></returns>
public string ReassembleSegmentedStatus(byte[][] segments)
{
var splitStatusStrings = new List<string>();
foreach (byte[] segment in segments)
{
string responseString = _gameEncoding.GetString(segment, 0, segment.Length);
var statusHeaderMatch = config.StatusHeader.PatternMatcher.Match(responseString);
if (statusHeaderMatch.Success)
{
splitStatusStrings.Insert(0, responseString.TrimEnd('\0'));
}
else
{
splitStatusStrings.Add(responseString.Replace(config.CommandPrefixes.RConResponse, "").TrimEnd('\0'));
}
}
return string.Join("", splitStatusStrings);
}
/// <summary>
/// Recombines multiple game messages into one
/// </summary>
/// <param name="payload"></param>
/// <returns></returns>
private string RecombineMessages(byte[][] payload)
{
if (payload.Length == 1)
{
return _gameEncoding.GetString(payload[0]).TrimEnd('\n') + '\n';
}
else
{
var builder = new StringBuilder();
for (int i = 0; i < payload.Length; i++)
{
string message = _gameEncoding.GetString(payload[i]).TrimEnd('\n') + '\n';
if (i > 0)
{
message = message.Replace(config.CommandPrefixes.RConResponse, "");
}
builder.Append(message);
}
builder.Append('\n');
return builder.ToString();
}
}
private async Task<byte[][]> SendPayloadAsync(byte[] payload, bool waitForResponse, TimeSpan overrideTimeout)
{
var connectionState = ActiveQueries[this.Endpoint];
var rconSocket = (Socket)connectionState.SendEventArgs.UserToken;
if (connectionState.ReceiveEventArgs.RemoteEndPoint == null &&
connectionState.SendEventArgs.RemoteEndPoint == null)
{
// setup the event handlers only once because we're reusing the event args
connectionState.SendEventArgs.Completed += OnDataSent;
connectionState.ReceiveEventArgs.Completed += OnDataReceived;
connectionState.SendEventArgs.RemoteEndPoint = this.Endpoint;
connectionState.ReceiveEventArgs.RemoteEndPoint = this.Endpoint;
connectionState.ReceiveEventArgs.DisconnectReuseSocket = true;
connectionState.SendEventArgs.DisconnectReuseSocket = true;
}
connectionState.SendEventArgs.SetBuffer(payload);
// send the data to the server
bool sendDataPending = rconSocket.SendToAsync(connectionState.SendEventArgs);
if (sendDataPending)
{
// the send has not been completed asynchronously
// this really shouldn't ever happen because it's UDP
if (!await Task.Run(() => connectionState.OnSentData.Wait(StaticHelpers.SocketTimeout(1))))
{
using(LogContext.PushProperty("Server", Endpoint.ToString()))
{
_log.LogWarning("Socket timed out while sending RCon data on attempt {attempt}",
connectionState.ConnectionAttempts);
}
rconSocket.Close();
throw new NetworkException("Timed out sending RCon data", rconSocket);
}
}
if (!waitForResponse)
{
return new byte[0][];
}
connectionState.ReceiveEventArgs.SetBuffer(connectionState.ReceiveBuffer);
// get our response back
bool receiveDataPending = rconSocket.ReceiveFromAsync(connectionState.ReceiveEventArgs);
if (receiveDataPending)
{
_log.LogDebug("Waiting to asynchronously receive data on attempt #{connectionAttempts}", connectionState.ConnectionAttempts);
if (!await Task.Run(() => connectionState.OnReceivedData.Wait(
new[]
{
StaticHelpers.SocketTimeout(connectionState.ConnectionAttempts),
overrideTimeout
}.Max())))
{
if (connectionState.ConnectionAttempts > 1) // this reduces some spam for unstable connections
{
using (LogContext.PushProperty("Server", Endpoint.ToString()))
{
_log.LogWarning(
"Socket timed out while waiting for RCon response on attempt {attempt} with timeout delay of {timeout}",
connectionState.ConnectionAttempts,
StaticHelpers.SocketTimeout(connectionState.ConnectionAttempts));
}
}
rconSocket.Close();
throw new NetworkException("Timed out receiving RCon response", rconSocket);
}
}
rconSocket.Close();
return GetResponseData(connectionState);
}
private byte[][] GetResponseData(ConnectionState connectionState)
{
var responseList = new List<byte[]>();
int totalBytesRead = 0;
foreach (int bytesRead in connectionState.BytesReadPerSegment)
{
responseList.Add(connectionState.ReceiveBuffer
.Skip(totalBytesRead)
.Take(bytesRead)
.ToArray());
totalBytesRead += bytesRead;
}
return responseList.ToArray();
}
private void OnDataReceived(object sender, SocketAsyncEventArgs e)
{
_log.LogDebug("Read {bytesTransferred} bytes from {endpoint}", e.BytesTransferred, e.RemoteEndPoint);
// this occurs when we close the socket
if (e.BytesTransferred == 0)
{
ActiveQueries[this.Endpoint].OnReceivedData.Set();
return;
}
if (sender is Socket sock)
{
var state = ActiveQueries[this.Endpoint];
state.BytesReadPerSegment.Add(e.BytesTransferred);
try
{
// we still have available data so the payload was segmented
if (sock.Available > 0)
{
state.ReceiveEventArgs.SetBuffer(state.ReceiveBuffer, e.BytesTransferred, state.ReceiveBuffer.Length - e.BytesTransferred);
if (!sock.ReceiveAsync(state.ReceiveEventArgs))
{
_log.LogDebug("Read {bytesTransferred} synchronous bytes from {endpoint}", state.ReceiveEventArgs.BytesTransferred, e.RemoteEndPoint);
// we need to increment this here because the callback isn't executed if there's no pending IO
state.BytesReadPerSegment.Add(state.ReceiveEventArgs.BytesTransferred);
ActiveQueries[this.Endpoint].OnReceivedData.Set();
}
}
else
{
ActiveQueries[this.Endpoint].OnReceivedData.Set();
}
}
catch (ObjectDisposedException)
{
ActiveQueries[this.Endpoint].OnReceivedData.Set();
}
}
}
private void OnDataSent(object sender, SocketAsyncEventArgs e)
{
_log.LogDebug("Sent {byteCount} bytes to {endpoint}", e.Buffer?.Length, e.ConnectSocket?.RemoteEndPoint);
ActiveQueries[this.Endpoint].OnSentData.Set();
}
}
}