| | | 1 | | using System; |
| | | 2 | | using System.Collections.Generic; |
| | | 3 | | using System.Linq; |
| | | 4 | | using System.Net.WebSockets; |
| | | 5 | | using System.Threading; |
| | | 6 | | using System.Threading.Tasks; |
| | | 7 | | using Jellyfin.Api.Extensions; |
| | | 8 | | using MediaBrowser.Controller.Net; |
| | | 9 | | using MediaBrowser.Controller.Net.WebSocketMessages.Outbound; |
| | | 10 | | using MediaBrowser.Controller.Session; |
| | | 11 | | using Microsoft.AspNetCore.Http; |
| | | 12 | | using Microsoft.Extensions.Logging; |
| | | 13 | | |
| | | 14 | | namespace Emby.Server.Implementations.Session |
| | | 15 | | { |
| | | 16 | | /// <summary> |
| | | 17 | | /// Class SessionWebSocketListener. |
| | | 18 | | /// </summary> |
| | | 19 | | public sealed class SessionWebSocketListener : IWebSocketListener, IDisposable |
| | | 20 | | { |
| | | 21 | | /// <summary> |
| | | 22 | | /// The timeout in seconds after which a WebSocket is considered to be lost. |
| | | 23 | | /// </summary> |
| | | 24 | | private const int WebSocketLostTimeout = 60; |
| | | 25 | | |
| | | 26 | | /// <summary> |
| | | 27 | | /// The keep-alive interval factor; controls how often the watcher will check on the status of the WebSockets. |
| | | 28 | | /// </summary> |
| | | 29 | | private const float IntervalFactor = 0.2f; |
| | | 30 | | |
| | | 31 | | /// <summary> |
| | | 32 | | /// The ForceKeepAlive factor; controls when a ForceKeepAlive is sent. |
| | | 33 | | /// </summary> |
| | | 34 | | private const float ForceKeepAliveFactor = 0.75f; |
| | | 35 | | |
| | | 36 | | /// <summary> |
| | | 37 | | /// The WebSocket watchlist. |
| | | 38 | | /// </summary> |
| | 19 | 39 | | private readonly HashSet<IWebSocketConnection> _webSockets = new HashSet<IWebSocketConnection>(); |
| | | 40 | | |
| | | 41 | | /// <summary> |
| | | 42 | | /// Lock used for accessing the WebSockets watchlist. |
| | | 43 | | /// </summary> |
| | 19 | 44 | | private readonly Lock _webSocketsLock = new(); |
| | | 45 | | |
| | | 46 | | private readonly ISessionManager _sessionManager; |
| | | 47 | | private readonly ILogger<SessionWebSocketListener> _logger; |
| | | 48 | | private readonly ILoggerFactory _loggerFactory; |
| | | 49 | | |
| | | 50 | | /// <summary> |
| | | 51 | | /// The KeepAlive cancellation token. |
| | | 52 | | /// </summary> |
| | | 53 | | private System.Timers.Timer _keepAlive; |
| | | 54 | | |
| | | 55 | | /// <summary> |
| | | 56 | | /// Initializes a new instance of the <see cref="SessionWebSocketListener" /> class. |
| | | 57 | | /// </summary> |
| | | 58 | | /// <param name="logger">The logger.</param> |
| | | 59 | | /// <param name="sessionManager">The session manager.</param> |
| | | 60 | | /// <param name="loggerFactory">The logger factory.</param> |
| | | 61 | | public SessionWebSocketListener( |
| | | 62 | | ILogger<SessionWebSocketListener> logger, |
| | | 63 | | ISessionManager sessionManager, |
| | | 64 | | ILoggerFactory loggerFactory) |
| | | 65 | | { |
| | 19 | 66 | | _logger = logger; |
| | 19 | 67 | | _sessionManager = sessionManager; |
| | 19 | 68 | | _loggerFactory = loggerFactory; |
| | 19 | 69 | | _keepAlive = new System.Timers.Timer(TimeSpan.FromSeconds(WebSocketLostTimeout * IntervalFactor)) |
| | 19 | 70 | | { |
| | 19 | 71 | | AutoReset = true, |
| | 19 | 72 | | Enabled = false |
| | 19 | 73 | | }; |
| | 19 | 74 | | _keepAlive.Elapsed += KeepAliveSockets; |
| | 19 | 75 | | } |
| | | 76 | | |
| | | 77 | | /// <inheritdoc /> |
| | | 78 | | public void Dispose() |
| | | 79 | | { |
| | 19 | 80 | | if (_keepAlive is not null) |
| | | 81 | | { |
| | 19 | 82 | | _keepAlive.Stop(); |
| | 19 | 83 | | _keepAlive.Elapsed -= KeepAliveSockets; |
| | 19 | 84 | | _keepAlive.Dispose(); |
| | 19 | 85 | | _keepAlive = null!; |
| | | 86 | | } |
| | | 87 | | |
| | | 88 | | lock (_webSocketsLock) |
| | | 89 | | { |
| | 38 | 90 | | foreach (var webSocket in _webSockets) |
| | | 91 | | { |
| | 0 | 92 | | webSocket.Closed -= OnWebSocketClosed; |
| | | 93 | | } |
| | | 94 | | |
| | 19 | 95 | | _webSockets.Clear(); |
| | 19 | 96 | | } |
| | 19 | 97 | | } |
| | | 98 | | |
| | | 99 | | /// <summary> |
| | | 100 | | /// Processes the message. |
| | | 101 | | /// </summary> |
| | | 102 | | /// <param name="message">The message.</param> |
| | | 103 | | /// <returns>Task.</returns> |
| | | 104 | | public Task ProcessMessageAsync(WebSocketMessageInfo message) |
| | 0 | 105 | | => Task.CompletedTask; |
| | | 106 | | |
| | | 107 | | /// <inheritdoc /> |
| | | 108 | | public async Task ProcessWebSocketConnectedAsync(IWebSocketConnection connection, HttpContext httpContext) |
| | | 109 | | { |
| | | 110 | | var session = await GetSession(httpContext, connection.RemoteEndPoint?.ToString()).ConfigureAwait(false); |
| | | 111 | | if (session is not null) |
| | | 112 | | { |
| | | 113 | | EnsureController(session, connection); |
| | | 114 | | await KeepAliveWebSocket(connection).ConfigureAwait(false); |
| | | 115 | | } |
| | | 116 | | else |
| | | 117 | | { |
| | | 118 | | _logger.LogWarning("Unable to determine session based on query string: {0}", httpContext.Request.QuerySt |
| | | 119 | | } |
| | | 120 | | } |
| | | 121 | | |
| | | 122 | | private async Task<SessionInfo?> GetSession(HttpContext httpContext, string? remoteEndpoint) |
| | | 123 | | { |
| | | 124 | | if (!httpContext.User.Identity?.IsAuthenticated ?? false) |
| | | 125 | | { |
| | | 126 | | return null; |
| | | 127 | | } |
| | | 128 | | |
| | | 129 | | var deviceId = httpContext.User.GetDeviceId(); |
| | | 130 | | if (httpContext.Request.Query.TryGetValue("deviceId", out var queryDeviceId)) |
| | | 131 | | { |
| | | 132 | | deviceId = queryDeviceId; |
| | | 133 | | } |
| | | 134 | | |
| | | 135 | | return await _sessionManager.GetSessionByAuthenticationToken(httpContext.User.GetToken(), deviceId, remoteEn |
| | | 136 | | .ConfigureAwait(false); |
| | | 137 | | } |
| | | 138 | | |
| | | 139 | | private void EnsureController(SessionInfo session, IWebSocketConnection connection) |
| | | 140 | | { |
| | 0 | 141 | | var controllerInfo = session.EnsureController<WebSocketController>( |
| | 0 | 142 | | s => new WebSocketController(_loggerFactory.CreateLogger<WebSocketController>(), s, _sessionManager)); |
| | | 143 | | |
| | 0 | 144 | | var controller = (WebSocketController)controllerInfo.Item1; |
| | 0 | 145 | | controller.AddWebSocket(connection); |
| | | 146 | | |
| | 0 | 147 | | _sessionManager.OnSessionControllerConnected(session); |
| | 0 | 148 | | } |
| | | 149 | | |
| | | 150 | | /// <summary> |
| | | 151 | | /// Called when a WebSocket is closed. |
| | | 152 | | /// </summary> |
| | | 153 | | /// <param name="sender">The WebSocket.</param> |
| | | 154 | | /// <param name="e">The event arguments.</param> |
| | | 155 | | private void OnWebSocketClosed(object? sender, EventArgs e) |
| | | 156 | | { |
| | 0 | 157 | | if (sender is null) |
| | | 158 | | { |
| | 0 | 159 | | return; |
| | | 160 | | } |
| | | 161 | | |
| | 0 | 162 | | var webSocket = (IWebSocketConnection)sender; |
| | 0 | 163 | | _logger.LogDebug("WebSocket {0} is closed.", webSocket); |
| | 0 | 164 | | RemoveWebSocket(webSocket); |
| | 0 | 165 | | } |
| | | 166 | | |
| | | 167 | | /// <summary> |
| | | 168 | | /// Adds a WebSocket to the KeepAlive watchlist. |
| | | 169 | | /// </summary> |
| | | 170 | | /// <param name="webSocket">The WebSocket to monitor.</param> |
| | | 171 | | private async Task KeepAliveWebSocket(IWebSocketConnection webSocket) |
| | | 172 | | { |
| | | 173 | | lock (_webSocketsLock) |
| | | 174 | | { |
| | | 175 | | if (!_webSockets.Add(webSocket)) |
| | | 176 | | { |
| | | 177 | | _logger.LogWarning("Multiple attempts to keep alive single WebSocket {0}", webSocket); |
| | | 178 | | return; |
| | | 179 | | } |
| | | 180 | | |
| | | 181 | | webSocket.Closed += OnWebSocketClosed; |
| | | 182 | | webSocket.LastKeepAliveDate = DateTime.UtcNow; |
| | | 183 | | |
| | | 184 | | _keepAlive.Start(); |
| | | 185 | | } |
| | | 186 | | |
| | | 187 | | // Notify WebSocket about timeout |
| | | 188 | | try |
| | | 189 | | { |
| | | 190 | | await SendForceKeepAlive(webSocket).ConfigureAwait(false); |
| | | 191 | | } |
| | | 192 | | catch (WebSocketException exception) |
| | | 193 | | { |
| | | 194 | | _logger.LogWarning(exception, "Cannot send ForceKeepAlive message to WebSocket {0}.", webSocket); |
| | | 195 | | } |
| | | 196 | | } |
| | | 197 | | |
| | | 198 | | /// <summary> |
| | | 199 | | /// Removes a WebSocket from the KeepAlive watchlist. |
| | | 200 | | /// </summary> |
| | | 201 | | /// <param name="webSocket">The WebSocket to remove.</param> |
| | | 202 | | private void RemoveWebSocket(IWebSocketConnection webSocket) |
| | 0 | 203 | | { |
| | | 204 | | lock (_webSocketsLock) |
| | | 205 | | { |
| | 0 | 206 | | if (_webSockets.Remove(webSocket)) |
| | | 207 | | { |
| | 0 | 208 | | webSocket.Closed -= OnWebSocketClosed; |
| | | 209 | | } |
| | | 210 | | else |
| | | 211 | | { |
| | 0 | 212 | | _logger.LogWarning("WebSocket {0} not on watchlist.", webSocket); |
| | | 213 | | } |
| | | 214 | | |
| | 0 | 215 | | if (_webSockets.Count == 0) |
| | | 216 | | { |
| | 0 | 217 | | _keepAlive.Stop(); |
| | | 218 | | } |
| | 0 | 219 | | } |
| | 0 | 220 | | } |
| | | 221 | | |
| | | 222 | | /// <summary> |
| | | 223 | | /// Checks status of KeepAlive of WebSockets. |
| | | 224 | | /// </summary> |
| | | 225 | | private async void KeepAliveSockets(object? o, EventArgs? e) |
| | | 226 | | { |
| | | 227 | | List<IWebSocketConnection> inactive; |
| | | 228 | | List<IWebSocketConnection> lost; |
| | | 229 | | |
| | | 230 | | lock (_webSocketsLock) |
| | | 231 | | { |
| | | 232 | | _logger.LogDebug("Watching {0} WebSockets.", _webSockets.Count); |
| | | 233 | | |
| | | 234 | | inactive = _webSockets.Where(i => |
| | | 235 | | { |
| | | 236 | | var elapsed = (DateTime.UtcNow - i.LastKeepAliveDate).TotalSeconds; |
| | | 237 | | return (elapsed > WebSocketLostTimeout * ForceKeepAliveFactor) && (elapsed < WebSocketLostTimeout); |
| | | 238 | | }).ToList(); |
| | | 239 | | lost = _webSockets.Where(i => (DateTime.UtcNow - i.LastKeepAliveDate).TotalSeconds >= WebSocketLostTimeo |
| | | 240 | | } |
| | | 241 | | |
| | | 242 | | if (inactive.Count > 0) |
| | | 243 | | { |
| | | 244 | | _logger.LogInformation("Sending ForceKeepAlive message to {0} inactive WebSockets.", inactive.Count); |
| | | 245 | | } |
| | | 246 | | |
| | | 247 | | foreach (var webSocket in inactive) |
| | | 248 | | { |
| | | 249 | | try |
| | | 250 | | { |
| | | 251 | | await SendForceKeepAlive(webSocket).ConfigureAwait(false); |
| | | 252 | | } |
| | | 253 | | catch (WebSocketException exception) |
| | | 254 | | { |
| | | 255 | | _logger.LogInformation(exception, "Error sending ForceKeepAlive message to WebSocket."); |
| | | 256 | | lost.Add(webSocket); |
| | | 257 | | } |
| | | 258 | | } |
| | | 259 | | |
| | | 260 | | lock (_webSocketsLock) |
| | | 261 | | { |
| | | 262 | | if (lost.Count > 0) |
| | | 263 | | { |
| | | 264 | | _logger.LogInformation("Lost {0} WebSockets.", lost.Count); |
| | | 265 | | foreach (var webSocket in lost) |
| | | 266 | | { |
| | | 267 | | // TODO: handle session relative to the lost webSocket |
| | | 268 | | RemoveWebSocket(webSocket); |
| | | 269 | | } |
| | | 270 | | } |
| | | 271 | | } |
| | | 272 | | } |
| | | 273 | | |
| | | 274 | | /// <summary> |
| | | 275 | | /// Sends a ForceKeepAlive message to a WebSocket. |
| | | 276 | | /// </summary> |
| | | 277 | | /// <param name="webSocket">The WebSocket.</param> |
| | | 278 | | /// <returns>Task.</returns> |
| | | 279 | | private async Task SendForceKeepAlive(IWebSocketConnection webSocket) |
| | | 280 | | { |
| | | 281 | | await webSocket.SendAsync( |
| | | 282 | | new ForceKeepAliveMessage(WebSocketLostTimeout), |
| | | 283 | | CancellationToken.None).ConfigureAwait(false); |
| | | 284 | | } |
| | | 285 | | } |
| | | 286 | | } |